pre calc
posted by Rebekah on .
I have a few problems from my homework that I am having trouble with.
#1 Find the difference quotient of f foreach function
f(x)=1/(x+3)
I got 2x+6
#2 Express the area of an isosceles right triangle as a function of the length x of one of the two eual sides
Thanks

The difference quotient,
∆f/∆x = [f(x+h)f(x)]/h
= [1/((x+h)+3)  1/(x+3)]/h
= 1/h [(x+3)  (x+h+3)] / (x+h+3)(x+3)
= 1/h (h)/(x+h+3)(x+3)
= 1/[(x+h+3)(x+3)]
The legs are x and x. One leg is the base, the other leg is the height, so the area is 1/2 bh = 1/2 x^2
Why can't the hypotenuse be one of the equal sides? Because the hypotenuse is longer than either leg. 
for the second problem what is th height??

ohh wait ok that was me just having a dumb moment haha. THANKS sooo much:)