CPhill

mGD = mGF + mFD   .......so.....

mGD = 43 + 77 = 120°

Note, Rose98, these are all central angles. And central angles always equal the measure of their intercepted arcs!!!

BTW..for extra credit....what is mCD ????

  (y-3)^2=8(x-5)

Let's see how Melody arrived at this......

Writing this in a slightly different form, we have

 (y-3)^2=4p(x-5)   where "p" is the distance (horizontal, in this case) between the x coordinate of the vertex and the x coordinate of the focal point.

So...we have.....

4p = 8   ..... and solving for "p"  we have

p = 2    ........i.e., the focal point is 2 units to the "right" from the vertex......thus......

The vertex is (5,3) and the focus is (7,3)......just as Melody found !!!!

For a "sideways" parabola that opens to the right, we add "p" to the x coordinate of the vertex. For one that opens to the left, we subtract "p" from the x coordinate of the vertex.

6) To convert from C to F we have......

F = (9/5)C + 32

So we have

F = (9/5)*(-74) + 32 = -101.2F

Pretty easy....(and pretty cold, too!!)

5)   B = (q + z/3)f

This is easy......divide both sides by f.....we have

B/f = q + z/3      ........subtract z/3 from each side

B/f - z/3  = q     

........We can make this look a little "nicer" by geeting a common denominator on the left

[3B - zf] / [3f] = q

4)  I assume this is A = (1/3)*pi*(t^2)*r  .... using 3.14 for "pi"...we have

Just divide both sides by  (1/3)*3.14*(t^2)

So we get

A / [ (1/3)*3.14*(t^2)] = r

3A/ [3.14*(t^2)]  = r ≈ .955A / t^2

3) Using P = 2(W + L) we have

86 =2(W + 34)     Divide both sides by 2

43 = W + 34        Subtract 34 from both sides

9 =W = 9cm

2) A = L * W

104 = L*16   Divide both sides by 16

104/16 = L = 26/4 = 13/2 = 6.5 in

1) Using C = 2*pi*r  we have

18.8 = 2*3.14*r

18.8 = 6.28*r     Divide both sides by 6.28

18.8/6.28 = r = 2.99 = 3

ND's answer IS correct......However, I usually like to reduce before multiplying, if we can.

Notice that 16/48 = 1/3

Now.......1/3 * 81 = 27

This way, we don't have to deal with "bigger" numbers.......

I'll bet I know what you might be doing wrong, rosala

It's in the second set of parenthesis.....

Remember that we're multiplyig the 7.7 x 10 before subtracting the "1"

Try it now......