Question 38

Mathematics Trigonometric Equations Hard

If the roots of the quadratic equation \(x^2+px+q=0\) are tan 30° and tan 15° respectively, then the value of 2 + q - p is

(A) 3
(B) 0
(C) 1
(D) 2
✓ Correct Answer: Option A Verified Solution

📘 Step-by-Step Solution & Detailed Explanation:

We know that: \[ (1 + \tan \theta)(1 + \tan (45^\circ - \theta)) = 2. \] Substituting \( \theta = 30^\circ \) and \( 45^\circ - \theta = 15^\circ \), we have: \[ (1 + \tan 30^\circ)(1 + \tan 15^\circ) = 2. \] Let the roots be \( \alpha \) and \( \beta \). Then: \[ (1 + \alpha)(1 + \beta) = 2 \quad \Rightarrow \quad 1 + \alpha + \beta + \alpha \beta = 2. \] Simplifying: \[ \alpha \beta + \alpha + \beta - 1 = 0. \] Substitute \( \alpha + \beta = q \) and \( \alpha \beta = p \): \[ p + q - 1 = 0 \quad \Rightarrow \quad q - p = 1. \] Thus: \[ 2 + q - p = 3 \]

Practice Similar Trigonometric Equations Questions

Reinforce your conceptual grasp with related questions from NIMCET 2022:

Q13 If \(cosecθ + cot θ=2\), then the value of \(cosecθ\) is
Solve →
Q14 The solution of the equation \( 4cos 2x+6 sin 2x=5\) are
Solve →
Q45 If \(cos -1 x/2+cos -1 y/3= \), then \(9x 2-12xy cos +4y 2\) is
Solve →
Q1 Inverse of the function \(f(x)= 10 x-10 -x 10 x +10 -x \) is
Solve →
Q2 Let \( a , b , c \) be distinct non-negative numbers. If the vectors \(a i...
Solve →
Full-Length Test Series

Prepare for NIMCET Under Real Exam Conditions

Take timed full-length mock tests with authentic question distributions, negative marking (+12/-3 in Math), and instant All India Rank calculation.

Start Free Mock Test Series →