Question
Mathematics Question on Trigonometric Equations
y=tan−1(secx3−tanx3),2π<x3<23π, then
A
xy′′+2y′=0
B
x2y′′−6y+23π
C
x2y″–6y+3π=0
D
xy″–4y′=0
Answer
x2y′′−6y+23π
Explanation
Solution
x3=θ⇒2θ∈(4π,43π)
∴y=tan–1(secθ–tanθ)
= tan−1(cosθ1−sinθ)
∴y=4π−2θ.
y=4π−2x3
∴y′=2−3x2
y′′=–3x
∴x2y′′−6y+23π=0
Hence, the correct option is (B): x2y′′−6y+23π