Are You Good At Math Grade 11 Material. Help Me Solve This

Grade 11 math help!!!! 10 points for best answer?

1) The half-life formula is y=x*2^(-t/24360)
where x is the original amount (in gram), and y the amount after t years.
Change this formula to find t for a given x and y:
Log2(y) = Log2[x * 2^(-t/24360)]
or:
Log2(y) = Log2(x) - t/24360
so:
t = 24360 * [Log2(x) - Log2(y)]
or:
t = 24360 * [Log2(x/y)]
Replace the values for x and y (x=10, y=1):
t = 24360 * Log2(10) ~= 23460 * 3.321928095 ~= 80 922 years

4) The double-life formula is y=x*2^(t/20)
where x is the original amount (of bacteria), and y the amount after t minutes.
Change this formula to find t for a given x and y:
Log2(y) = Log2[x * 2^(t/20)]
or:
Log2(y) = Log2(x) + t/20
so:
t = 20 * [Log2(y) - Log2(x)]
or:
t = 20 * [Log2(y/x)]
Replace the values for x and y (x=50, y=250 000):
t = 20 * Log2(5000) ~= 20 * 12.28771238 ~= 246 minutes (i.e. 4 hours and 6 minutes)

9) This is a strange question, since you provide a linear equation and it can be simplified to y=6x-1. I would have expected a more complex function (was there a typo in your formula?). Anyway:
domain: R (the function is defined for all real numbers)
range: R (the function can return any real number)
x-intercepts: (x,y)=(1/6,0)
y-intercepts: (x,y)=(0,-1)
asymptotes: none.

Let me consider that you maybe wanted to type y=2/(3x) - 1, then:
domain: R \ {0} (the function is defined for all real numbers, except for x=0)
range: R \ {-1} (the function can return any real number, except -1)
x-intercepts: (x,y)=(2/3,0)
y-intercepts: none, since the function is not defined for x=0
two asymptotes: x=0 and y=-1

Or maybe you meant y=2/(3x - 1), then:
domain: R \ {1/3} (the function is defined for all real numbers, except for x=1/3)
range: R \ {0} (the function can return any real number, except 0)
x-intercepts: none, since the function result cannot be 0
y-intercepts: (0,-2)
two asymptotes: x=1/3 and y=0

Easiest way to answer grade 11 math?

θ = 1/2 * arccos(0.6420)

Edit: so if your working with degrees your general solution would be:

θ = ±1/2 * arccos(0.6420) + k * 180° => k being an integer, and 180° or pi radians, is the 1/2 period of the cosine function, since it repeats evrery 360° or 2pi radians.
first the negative value:
θ = -1/2 * arccos(0.6420) + k * 180° => k can only be 1 , 2 since k=0 gives you a negative angle which doesn't make much sense, and k = 3 puts θ outside the interval (0 , 360), then:
θ = -1/2 * 50° + 180° = 180 - 25 = 155° => one of your values in the interval(0 , 360)
k = 2=> 360 - 25 = 335°=> another valid value
now you positive value:
θ = 1/2 * arccos(0.6420) + k * 180°
for k = 0=> θ = 1/2 * 50 =25° => another valid value
k= 1=> θ =25° + 180 = 205° => valid
k = 2 => puts θ outside (0 , 360) interval
hence you values in the (0, 360) interval are:
θ = 25° , 155° , 205° & 335°

I need help with grade 11 math?

This requires a little more than just compound interest: http://math2.org/math/general/interest.h...

The first payment earned compound interest for 12×30 months for a total of

          450 × (1+x/12)^(12×30)

where "x" is the desired interest rate.
The second payment is only earning interest for 12×30-1 months:

          450 × (1+x/12)^(12×30-1)

Then the third payment adds:

          450 × (1+x/12)^(12×30-2)

30 years later, the grand total becomes:

          450,000 = 450 × Σ(1+x/12)^N ,   for N=0 to 360.

Which, curtesy of the geometric series formula: http://mathworld.wolfram.com/GeometricSe... , becomes:

          450,000 = 450 [ (1+x/12)^361 - 1 ] / (x/12)

This is just the future value annuity formula: http://en.wikipedia.org/wiki/Time_value_...

Simplifying:      (1+x/12)^361 - 1000(x/12) - 1 = 0

But that is not easy to solve! Most high school textbooks will just tell you to plug it into your graphing calculator to get x=0.05945, just over 5.9%. Calculus students might use Newton's method http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/approx/newton.html but even that converges very slowly. I don't see any way to do this with high school math, beyond the basic elementary school technique of "guess and check".

Note that I have assumed payments starting 30 years ago (360 months) and finishing now, for a total of 361 payments of $450. The answer you give arises from payments that start 359 months ago, finishing now.

I failed my grade 10 math final but I tried really hard?

I studied so hard for this exam, i put in hours of studying but i still failed. Math really isn't my subject i'm much better at science but i don't understand how i failed after putting in so much effort. During math classes i always listened and took good notes but the best i could get was a 69%.There's people who get an 80 when I study more then they do. My mom expects an 80% from me, and this final brought me down to 56. I'm really sad right now, and i feel like i can't do anything right anymore. I don't know how to tell my mom i failed because i don't want to disappoint her and she's going to get REALLY angry at me, to a point where she's going to yell and scream at me. Please help!

Can you solve these math questions for me? And show steps!?

I'll solve three of these, but you should be able to do them on your own.

1a. 2x+(1/2) = (1/2).
Subtract 1/2 from both sides. You get 2x=0. To get "x," divide both sides by 2 so you can isolate the x. You get x = 0/2 = 0.

1b. m/2.5+1.5=0.8.
Subtract 1.5 from both sides. m/2.5+1.5-1.5 = m/2.5. 0.8-1.5= -0.7. So, we end up with m/2.5=-0.7.
Now, multiply both sides by 2.5, so you can isolate the "m." (m/2.5)*2.5=m, and -0.7*2.5= -1.75. Thus, m= -1.75.

1c. 4x-7=29. Add 7 to both sides. 4x-7+7=29+7=36. Now, we're stuck with 4x=36. To isolate the x, divide both sides by 4. (4x)/4=36/4=9.
So, x=9.

I should warn you that you should not let someone online answer all these questions for you. If you don't practice them yourself, you'll never pass the exam properly. Michael Jordan didn't ask other basketball players to stop what they were doing during practice and shoot the ball on his behalf :)

So go over how I did those problems, and apply the same steps to solve the other problems.

Good luck!

I'm worried about my grades? Have all straight A's besides math?

I'm in grade 11 and I have accounting, english, marketing and math. I have all straight A's, except for math. I'm getting a 56 FMLLL. This is the only subject I struggle in, and it is really pulling my average down :( I really want to get into university but right now I don't have the 80 average I need because I have an 80, 82, 89 and 56 right now. I go see my teacher 2-3 times a week, and like NO ONE in my class stays after school. Thing is when he teaches a lesson I get it, he is a very good teacher, and afterwards I start the homework. It's all good at the beginning, but when it gets more complicated I get stuck. I ask my teacher about it. But we learn so much in one unit I get mixed up and forget things. Funny thing is, I got an 83% in math in grade 9, and an 68% in grade 10...

My math teacher thinks I don't need a tutor because I seem to understand the concepts, but don't know when to interpret it in a question, so he doesn't think I need a tutor. I don't know what to do :(

Help me with these math problems please?

What is the contrapositive of the following conditional?
If a triangle is equilateral, it is equiangular.

What is the converse of the following conditional?
If two segments are congruent, then they have equal measures.

What is the converse of the following theorem?
If a point is on the bisector of an angle, it is equidistant from the sides of the angle.

What is the converse of the following conditional?
If two angles are supplements of the same angle, then they are congruent.

What is the inverse of the following conditional?
If two lines are perpendicular, then they form four right angles.

What is the contrapositive of the following conditional?
If a point is on the bisector of an angle, then it is equidistant from the sides of the angle.

What is the converse of the following conditional?
If there are no clouds in the sky, it will not rain.

Choose the correct word to complete the statement.
Through a point not on a line, there is exactly one line _______ to the given line.
Skew
Scalene
Perpendicular

If a person runs in Softee Shoes, that person cares about his ankles.
Choose the inverse of the statement above.

If you buy a Smatchy Watch before December 25, you save 25%.
Choose the converse of the statement above.

What is the name of the angle formed by the intersection of two noncollinear rays AB and AC?

Triangle ΔRST is isosceles with RS=ST. What are the base angles?

Points A, B and C lie on a straight line. B is between A and C. If AB=24 and AB=2/3AC, what is 1/4AC?

Point R bisects PQ. Which conclusion is correct?

D is the midpoint of AC in triangle ΔABC. Which word best describes BD?

ER bisects segment LM at S. Which conclusion can be drawn?

The measure of an angle is 40º less than the measure of its supplement. What is the measure of the angle and of its supplement?

AB is perpendicular to CE at E. Which conclusion can be drawn?

∠AEF and ∠AED form a linear pair. If m∠AEF=x, what is m∠AED?

What property gives the reason for this statement?
If points A, B, C and D are collinear, B lies between A and C, C lies between B and D, and AB=CD, then AC=BD.

Points A, E and B are collinear. Point E is on LM. What is the point of intersection of AB and LM?