What is f(x) = int (3x+1)^2-6x+1 dxf(x)=∫(3x+1)2−6x+1dx if f(2) = 1 f(2)=1?
1 Answer
May 17, 2018
Explanation:
"expand and simplify"expand and simplify
rArrint(9x^2+6x+1-6x+1)dx⇒∫(9x2+6x+1−6x+1)dx
=int(9x^2+2)dx=∫(9x2+2)dx
"integrate each term using the "color(blue)"power rule"integrate each term using the power rule
•color(white)(x)int(ax^n)=a/(n+1)x^(n+1)ton!=-1∙x∫(axn)=an+1xn+1→n≠−1
rArrint(9x^2+2)dx=3x^3+2x+c⇒∫(9x2+2)dx=3x3+2x+c
"where c is the constant of integration"where c is the constant of integration
"to find c use "f(2)=1to find c use f(2)=1
rArr3(2)^3+2(2)+c=1⇒3(2)3+2(2)+c=1
rArrc=1-28=-27⇒c=1−28=−27
rArr3x^3+2x-27⇒3x3+2x−27