# Math Help - Pre-calculus Problems

1. ## Pre-calculus Problems

Can someone please help me with these problems? I have tried working them out, but I can't seem to get a solution. Please see attachment. Thanks

2. Originally Posted by fw_mathis
Can someone please help me with these problems? I have tried working them out, but I can't seem to get a solution. Please see attachment. Thanks
Hello,

For #1, plug in the x values given into "x"; so,

y = 1/(-2 - 2);

y = 1/(-2 - 1);... and so forth

y = -1/4, -1/3, -1/2, -1, undefined (since you get 1/0), 1 for x = -2, -1, 0, 1, 2, 3, respectively.

2.)

x - 2*sqrt(x) = 0

-2*sqrt(x) = -x

2*sqrt(x) = x

sqrt(x) = x/2

Square both sides;

x = x^2/4

x - x^2/4 = 0

(-x^2 + 4x)/4 = 0

-x^2 + 4x = 0

-x*(x - 4) = 0

x = 0 V x = 4

3. Originally Posted by fw_mathis
Can someone please help me with these problems? I have tried working them out, but I can't seem to get a solution. Please see attachment. Thanks
3.)

Let (0, 0) be your starting position.

You're at (75, 65);

You could either find the hypotenuse or use the distance formula (which is the same thing).

Using the distance formula:

d = sqrt((x_2 - x_1)^2 + (y_2 - y_1)^2)

d = sqrt((75 - 0)^2 + (65 - 0)^2)

d = sqrt(75^2 + 65^2)

d = sqrt(9850)

d = 5*sqrt(394)

d ~ 99.25 kilometers

Pythag:

a^2 + b^2 = c^2

a = 65

b = 75

Which is the distance formula. Do you see how?

65^2 + 75^2 = c^2 ...

4.) V = s^3

1000 = s^3

Solve for s;

s = 10 cm