Sunday

September 21, 2014

September 21, 2014

Posted by **Diana** on Friday, July 15, 2011 at 4:21pm.

f(x)=x^2-8x+16

could you please show me step by step i have been trying to figure it out for hours.

- precalc -
**Reiny**, Friday, July 15, 2011 at 5:32pmfirst one:

y = 4/(x-4)^2

inverse is

x = 4/(y-4)^2

solving this for y .....

(y-4)^2 = 4/x

y - 4 = ± 2/√x

y = 4 ± 2/√x

2nd .....

inverse is

x = y^2 - 8y + 16

y^2 - 8y + 16 - x = 0

use the quadratic equation

where a=1, b=-8 and c = 16-x to solve for y

- precalc -
**Diana**, Friday, July 15, 2011 at 5:50pmthanks i got the first one now!

for the second one I used the quadratic eqn and got 4 but that is not the answer?

- precalc -
**Reiny**, Friday, July 15, 2011 at 5:59pmy = (8 ± √(64-4(1)(16-x))/2

= (8 ± √(4x) )/2

= (8 ± 2√x)/2

= 4 ± √x

check: let x = 3 into the first

y = 9 - 24 + 16 = 1

put x = 1 into the second:

y = 4 ± √1 = 5 or 3

notice the the inverse of each of the equations is not a function.

**Answer this Question**

**Related Questions**

Physics - I'm trying to rearange this 0 = Xo + 2^-1 a t^2 for t I've been told ...

functions - For each problem, construct two composite functions, . Evaluate each...

math - Could you show me step by step how to find the inverse of this problem: ...

Math ( composite functions ) - I need some help with composite functions where ...

Math(Please check) - The following function is one-to-one; find its inverse f(x...

Math - Give the equation of the line that passes through point (1, 2) and is ...

Algebra - I'm trying to solve (5x-4)/(5x+4)=2/3. I don't know how to get the x's...

algebra functions - construct two composite functions, Evaluate each composite ...

Trig - Find the value of the six trigonometric functions. t = 7(pi)/4 Can you ...

Geometry Question plz help - Could someone please explain how to figure this out...