PYQ Vault
EbooksTutor

Identities for sin^4 + cos^4 and sin^6 + cos^6

This type of question, asked 2 times: 18 Apr 2026 S2, 12 May 2026 S2. All 2 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    18 Apr 2026 S2

    53
    Let fk(x)=1k(cos⁡kx+sin⁡kx)f_k(x) = \dfrac{1}{k}(\cos^k x + \sin^k x) where k∈Nk \in N, then f6(x)−f4(x)=…f_6(x) - f_4(x) = \ldots

    Tap an option to check your answer.

  2. Question 2

    12 May 2026 S2

    52
    If sin⁡4θ+cos⁡4θ=58,0<θ<π2\sin^4\theta + \cos^4\theta = \dfrac{5}{8}, 0 < \theta < \dfrac{\pi}{2}, then sin⁡2θ=…\sin 2\theta = \ldots

    Tap an option to check your answer.