(you forgot the 1)
try again ...
Find an equation of the tangent line to the graph of f at the indicated point
f(x)=x^{2}+1
(2, 5)
This is what I did:
First step - lim (x+△x)^{2}+1-(x+△x)^2)
△x->0 .........................△x
Plugged in 0 to every △x, which turns out to be 1/0, which is undefined
Second step - (x+△x)(x+△x)+1-(x+△x)(x+△x)
....................................△x
Turns into x^{2}+2△x+△x^{2}+1-x^{2}-2△x-△x^{2 } ....................................△x
I got lost here, I think I messed up on the 2nd parenthesis, because I thought I should have turned everything negative since there was a minus sign.
But then it cancels everything else except the +1
Can someone help me from here?
Thanks