Algebra 2 Homework?!?!?

Inverse functions can be hard to understand. Try this:

First, make f(x) y: y=5x+4

Next, switch x and y: x=5y+4

Now, just solve to get y alone: x-4=5x; (x-4)/5=y

To write it in function notation, write f^-1(x)=(x-4)/5.

After trying to solve problem after problem on yahooanswers, I honestly think most people dont learn a lot if I give them the answers. Heres a VERY similar problem. Just fill in the values from your own problem. (Hint: you will need to use the Quadratic Formula at the end!) Goodluck!!! QUESTION: The hypotenuse of a right triangle has a length of 13 cm. The sum of the lengths of the two legs is 17 cm. Find the lengths of the legs. Let a = length of one leg Let b = length of other leg We are told that: a + b = 10.23 --> b = 10.23 - b [1] The hypotenuse is 8.312. From Pythagorus: a² + b² = 8.312² [2] Substitute [1] into [2]: a² + (8.312 - b)² = 169 This simplifies to: 2a² - 34a + 120 = 0 Divide by 2: a² - 17a + 60 = 0 which factors: (a - 5)(a - 12) = 0 and has roots: a = 5, 12 Substitute into [1] and get: b = 12, 5 The lengths of the legs are 5 and 12 cm.

[first, for the sake of clarity, switch f(x) with y]

y=5x+4

[then, because this is how you find inverses, switch the (x)s and the (y)s]

x=5y+4

[now solve for, or "isolate" y]

x-4=5y

(x-4)/5=y

[so there's your answer, but I think inverse notation looks like this]

f^-1(x)=(x-4)/5

[alternatively,]

f^-1(x)=x/5+0.8

[or]

f^-1(x)=x/5+4/5

f(x)=5x+4 is the same as y=5x+4

to get the inverse switch y and x

and solve for y

x=5y+4

5y=x-4

y=(x-4)/5

replace y with inverse function notation

f^-1(x)=(x-4)/5

You start by making f(x) to y and rewriting the equation y=5x+4. Then, solve for x. To get your final answer, just switch the y to x, and x to y.

y= 5x+ 4 , subtract 4 ;

y-4=5x , now divide by 5

(y-4) / 5 = x , now switch the x and y

(x-4) / 5 = y , and that's your answer.

You should look this question on how to do it online here's a good site

http://www.uncwil.edu/courses/mat111hb/functions/i...

that way your not just taking some yahoo's answer and you learn something!

i have a question i have Algebra 1 and is this an additive inverse or a multiplicative and wow really sux having a teacher like that...well i would say since f(x)=y (yay just learned that today!!) then isnt' it

check out this website for help...http://education.yahoo.com/homework_help/math_help...

looks like it would help you and i hope i answered ur question

If you have f(x), what you want to do is exchange the y and x values, and then solve for the y value again.

In this case,

y=5x+4

x=5y+4

x-4=5y

(x-4)/5=y

well inverse means the oppiste so it would be

f(x)=-5x-4 i think

do you go to hanover and have ms.solomon