MHT CET202525 Apr 2025Morning ShiftMathematicsIndefinite IntegrationActual
d x 3 2 x+5 equals
Options
- A1 2 ⁻¹( x)+c , where c is the constant of integration.
- B1 2 ⁻¹ ( x 2 )+c, where c is the constant of integration.
- C1 4 ⁻¹ ( 1 2 x )+c , where c is the constant of integration.
- D1 4 ⁻¹( x)+ c , where c is the constant of integration.
Correct answer
C. 1 4 ⁻¹ ( 1 2 x )+c , where c is the constant of integration.
Step-by-step solution
Let I = d x 3 2x + 5 . Using the trigonometric substitution 2x = 1 - ^2 x 1 + ^2 x , we transform the integral: I = d x 3 ( 1 - ^2 x 1 + ^2 x ) + 5 = 1 + ^2 x 8 + 2 ^2 x d x . Recognizing that 1 + ^2 x = ^2 x , we have I = ^2 x d x 8 + 2 ^2 x . With the substitution t = x , where d t = ^2 x d x , the integral becomes: I = d t 8 + 2t^2 = 1 2 d t 4 + t^2 . Applying the standard antiderivative formula d u a^2 + u^2 = 1 a ( u a ) + C with a = 2 , we obtain: I = 1 4 ( t 2 ) + C . Substituting back t = x gives: I = 1 4 (