Question

find an equation of the tangent line of x^4+2x^2-x at (1,2)

Answer 1

calculus based?

Answer 2

differentiate

\[dy/dx = 4x^3 + 4x -1\]

substitute x = 1 into the derivative to find the gradient at (1, 2)

then use point gradient formula to find the equation of the tangent

you should get y = 7x -5 i think

Answer 3

perfect! if that's calculus based :)

Answer 4

ok so you do plug in the x into the derivative. i was a little confused on that thanks!

Answer 5

yes x =1 is substituted into the derivative to find the gradient