/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}

91Ó°ÊÓ

Establish each identity
sin3θcosθ-sinθcos3θsin2θ=1

Short Answer

Expert verified

The derivation of the equation sin3θcosθ-sinθcos3θsin2θ=1is

sin3θcosθ-sinθcos3θsin2θ=3sinθ-4sin3θcosθ-sinθ4cos3θ-3cosθsin2θ=6sinθcosθ-4sinθcosθ(sin2θ+cos2θ)sin2θ=2sinθcosθsin2θ=2sinθcosθ2sinθcosθ=1

Step by step solution

01

Step 1. Given data

The given equation for derivation is

sin3θcosθ-sinθcos3θsin2θ=1

02

Step 2. Use of triple angle formula

Take left-hand side expression and use triple angle formula

sin3θcosθ-sinθcos3θsin2θ=3sinθ-4sin3θcosθ-sinθ4cos3θ-3cosθsin2θ=3sinθcosθ-4sin3θcosθ-4sinθcos3θ+3cosθsinθsin2θ=6sinθcosθ-4sinθcosθ(sin2θ+cos2θ)sin2θ=6sinθcosθ-4sinθcosθ(1)sin2θ=2sinθcosθsin2θ

03

Step 3. Use of double angle formula

Apply double angle formula

sin3θcosθ-sinθcos3θsin2θ=2sinθcosθsin2θsin3θcosθ-sinθcos3θsin2θ=2sinθcosθ2sinθcosθsin3θcosθ-sinθcos3θsin2θ=1

The left-hand side expression is equal to the right-hand side expression

So identity is stabilised

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.