Trigonometric Identities Level 2 Practice Quiz: Powers, Products and Extremes
Level 2 of the trigonometric identities series develops multi-step simplification: combining identities, higher powers of sine and cosine, and extreme values of shifted expressions. Aptitude360 designed this intermediate set for quant aptitude practice, and each question includes a written solution showing the identity used.
What this Level 2 trigonometry set tests
- Finding cosine or sine from a given sum of secant and tangent, or of cosecant and cotangent
- Maximum and minimum of sine-cosine combinations with a constant added or subtracted
- Minimum of expressions that mix secant squared with cosine squared
- Fourth, third and sixth powers of sine and cosine
- Long products of tangents and sums of logarithms of tangents
- Sums of sine squared over angles in arithmetic progression
- Eliminating theta when two variables are written in secant and tangent
Useful identity rules and formulas for Level 2
- Square of sum: \( (\sin\theta+\cos\theta)^{2}=1+2\sin\theta\cos\theta \)
- Fourth powers: \( \sin^{4}\theta+\cos^{4}\theta=1-2\sin^{2}\theta\cos^{2}\theta \)
- Tan plus cot: \( \tan\theta+\cot\theta=\dfrac{1}{\sin\theta\cos\theta} \)
- Complementary product: \( \tan\theta\times\tan(90^{\circ}-\theta)=1 \)
- AM-GM bound for \( a,b>0 \): \( a\sec^{2}\theta+b\cos^{2}\theta\ge2\sqrt{ab} \)
Preparation tips for intermediate identity problems
- Treat a constant added to a sine-cosine expression as a shift: the range moves up or down by that constant
- Pair angles from both ends of a long tangent product so each pair multiplies to one
- Rewrite higher powers using the square of sine squared plus cosine squared
- When a minus sign sits before a sine-cosine block, the maximum of the whole uses the minimum of the block
Who this set suits
Students who are comfortable with the basic identities and want firmer practice for SSC, banking and other aptitude exams.