Question

If sin(A-B)=sinA.cosB-cosA.sin B
So find 15°=?

Answer 1

Step-by-step explanation:

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Answer 2

given

sin(A-B)= sinAcosB- cosAsinB

again 15° can be written as

15°= 45°-30°

taking sin on both sides

sin15° = sin(45°-30°)

= sin45cos30-cos45sin30

(formula used)

= 1/√2× √3/2 - 1/√2×1/2

= √3/2√2 - 1/2√2

= (√3-1) / ( 2√2)

(taking common)

so. 15° = sin inv ( √3-1)/2√2

therefore the value of 15°

= sin invers ( √3-1) / 2√2