# Pre-Calc Line Problems.

• Jan 20th 2009, 12:35 PM
ClearSights
Pre-Calc Line Problems.
Ok, I have two questions I need help with....Here they are

First.

Write an equation of a line through (3,5) perpendicular to y=4.

Second.

f(x) = x^2 ; g(x) = 6x - 8 ; find all real numbers for which f(x) = g(x).

Any help would be greatly appreciated!
• Jan 20th 2009, 12:41 PM
earboth
Quote:

Originally Posted by ClearSights
Ok, I have two questions I need help with....Here they are

First.

Write an equation of a line through (3,5) perpendicular to y=4.

Second.

f(x) = x^2 ; g(x) = 6x - 8 ; find all real numbers for which f(x) = g(x).

Any help would be greatly appreciated!

to #1:

The line must be a parallel to the y-axis. Thus x = 3

to #2:

If f(x) = g(x) then $x^2=6x-8~\implies~x^2-6x+8=0~\implies~(x-2)(x-4)=0$

Therefore x = 2 or x = 4