Question

the graph of y = x^3 -9x^2 - 16x +1 has a slope of 5 at two points. Find the coordinates of the points

Answer 1

y'=3x^2-18x-16=5

Answer 2

solve for x

Answer 3

I know that y'= 3x^2-18x-16
0=3x^2-18-21
I am stuck

Answer 4

you have forgotten how to solve the quadratic\[3x^2-18x-21=0\]this is definately a skill you need to have down for calculus
first divide out the common factor of 3, then see if you can factor the equation
if not, use the quadratic formula

Answer 5

(3x-21)(x+1)..Is this correct

Answer 6

yeah, but you could factor out the 3\[3x^2-18x-21=0\implies x^2-6x-7=0\]\[\implies(x-7)(x+1)=0\]

Answer 7

x=7 x=-1 and i plugged it in the org equation..Thanks