Home › TS EAPCET (Engineering) › Mathematics › Trigonometric Functions › All angles at which the cosine of double the ang…
All angles at which the cosine of double the angle vanishes are given by
Ax = (2n+1)π/2
Bx = (2n+1)π/8
Cx = (2n+1)π/3
Dx = (2n+1)π/4
Answer & Solution
Correct answer: D. x = (2n+1)π/4
cos 2x = 0 needs 2x = (2n + 1)π/2, which gives x = (2n + 1)π/4.
Related questions
Inside (0, π/2), the angle where tan x equals its own reciprocal isThe least positive root of the equation sin 2x = sin x isAdding every root of 2 sin x cos x = sin x on [0, π] givesBetween 0 and 2π inclusive, how many angles satisfy sin 2x = 1?Solving sin x = sin α completely, with n an integer, givesTangent takes positive values in which pair of quadrants?A point has sine 3/5 and sits in the second quadrant; its cosine isHalving the angle inside a cosine stretches its repetition length to