How do you find the equation of the tangent line to the curve #y = x^4 + 9x^2 − x#, at (1, 9)?
1 Answer
May 9, 2018
Explanation:
#"we require the slope m and a point on the tangent"#
#•color(white)(x)m_(color(red)"tangent")=dy/dx" at x = 1"#
#dy/dx=4x^3+18x-1#
#x=1tody/dx=4+18-1=21#
#"using "m=21" and "(x_1,y_1)=(1,9)#
#y-9=21(x-1)#
#rArry=21x-12larrcolor(red)"equation of tangent"#
