how do i find (fog)(5) when f(x)=-4x+11, g(x)=2x-3

Question

anonymous · Answer

Try this hint...I have placed my response on another site since it is easier to type math over there. http://www.demonstranda.com/book/questionDetails/326

amistre64 · Answer

fog should be read as:  f, composed of, g; the (5) refers to the value to give to x

f(g) = -4g+11 ;  and g(x) = 2x-3;  at x = 5

agent0smith · Answer

fog(5) means f( g(5) ) 

this means you need to find the value of g(5) 

then plug THAT number into f(x)

anonymous · Answer

How would i find the value of g(5)?

agent0smith · Answer

g(x)=2x-3 so plug in 5 in place of x, into 2x-3

anonymous · Answer

i like to think of the functional notation like this:

$$f(x) = -4(x)+11$$

that way, if anything replaces x in the parentheses on the left, it does that same in the parentheses on the right.

so $$f\circ g(x) = f \left( g(x) \right)= -4\left( g(x) \right)+11=-4(2x-3)+11= -8x+12+11= -8x+23$$

anonymous · Answer

and then that x value is plugged into the f(x) equation?