If , then one of the most proper substitutions to evaluate…

MATHEMATICS · Single correct · CBSE · Mathematics · Integrals · Integrals

Problem

I=\int\frac{dx}{x-\sqrt{9x^2+4x+6}}

, then one of the most proper substitutions to evaluate

I

is: (1)

\sqrt{9x^2+4x+6}=u\pm3x

(2)

\sqrt{9x^2+4x+6}=3u\pm x

(3)

x=\frac{1}{t}

(4)

9x^2+4x+6=\frac{1}{t}