I am so lost, I have no idea what to do next.
Find the equation of the tangent line to the graph at the indicated point f(x) =x^2 +x ; a=-1
I started out using f(-1)= (-1+h)-(-1)/h
but i am so lost on what to do next.
I have tried to look at examples in the book, but i do not understand where they are getting some of the numbers from Please Help! Thank you.
f(x+h) = (x+h)^2 + x + h
= x^2 + 2 h x + h^2 + x + h
f(x) = x^2 + x
slope = [f(x+h) - f(x) ]/h
= [ 2 h x + h^2 + h ]/h
= 2 x + h + 1
now at the point x = -1, h --->0
and
slope = 2 x + 1
which is
-2 + 1 = -1
so
form of tangent is y = -1 x + b
now what is y at x = -1
y = (-1)^2 -1 = 0
so our tangent line is
y = -x