Skip to content
3.2(C) · Q101

Q.Evaluate: ∫3x+42x2+2x+1 dx\int \frac{3x+4}{\sqrt{2x^2+2x+1}}\,dx

Maharashtra MsbshseTextbookSubjectiveImportance★★★★★est
59% · 150/255 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

Derivative of the radicand 2x2+2x+12x^2+2x+1 is 4x+24x+2. Write 3x+4=A(4x+2)+B3x+4=A(4x+2)+B: 4A=3⇒A=344A=3\Rightarrow A=\dfrac34, 2A+B=4⇒B=522A+B=4\Rightarrow B=\dfrac52.

So ∫3x+42x2+2x+1dx=34∫4x+22x2+2x+1dx+52∫dx2x2+2x+1\displaystyle\int\dfrac{3x+4}{\sqrt{2x^2+2x+1}}dx=\dfrac34\int\dfrac{4x+2}{\sqrt{2x^2+2x+1}}dx+\dfrac52\int\dfrac{dx}{\sqrt{2x^2+2x+1}}.

First (of the form ∫f′/f=2f\int f'/\sqrt f=2\sqrt f): 34⋅22x2+2x+1=322x2+2x+1\dfrac34\cdot2\sqrt{2x^2+2x+1}=\dfrac32\sqrt{2x^2+2x+1}. …

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.