NIMCET 2026 — Mathematics PYQ
NIMCET | Mathematics | 2026If tan−1(3x)+tan−1(2x)=4π, then find the value of x.
Choose the correct answer:
- A.
2
- B.
1
- C.
∞
- D.
0
(Correct Answer)
0
Explanation
To solve the equation tan−1(3x)+tan−1(2x)=4π, we use the standard formula for the sum of inverse tangents:
tan−1(A)+tan−1(B)=tan−1(1−ABA+B)
Step 1: Apply the formula
Taking A=3x and B=2x:
tan−1(1−(3x)(2x)3x+2x)=4π
tan−1(1−6x25x)=4π
Step 2: Solve for x
Take the tangent of both sides:
1−6x25x=tan(4π)
Since tan(4π)=1:
1−6x25x=1
5x=1−6x2
6x2+5x−1=0
Step 3: Factor the quadratic equation
6x2+6x−x−1=0
6x(x+1)−1(x+1)=0
(6x−1)(x+1)=0
Explanation
To solve the equation tan−1(3x)+tan−1(2x)=4π, we use the standard formula for the sum of inverse tangents:
tan−1(A)+tan−1(B)=tan−1(1−ABA+B)
Step 1: Apply the formula
Taking A=3x and B=2x:
tan−1(1−(3x)(2x)3x+2x)=4π
tan−1(1−6x25x)=4π
Step 2: Solve for x
Take the tangent of both sides:
1−6x25x=tan(4π)
Since tan(4π)=1:
1−6x25x=1
5x=1−6x2
6x2+5x−1=0
Step 3: Factor the quadratic equation
6x2+6x−x−1=0
6x(x+1)−1(x+1)=0
(6x−1)(x+1)=0

