Question

Sin 25 into cos 65 + cos 25 into+ sin 65

Answer 1

Answer:

Step-by-step explanation:

Hello!

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we need a formula which is

sin( A + B ) = sinAcosB + cosAsinB

Given us,

sin25cos65 + cos25sin65

= sin( 25 + 65 )

= sin90

= 1

thanks

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Answer 2

sin 25° cos 65° + cos 25° sin 65°

= sin 25° cos (90° – 25°) + cos 25° sin (90° – 25°)

= sin 25° sin 25° + cos 25° + cos 25°

= sin2 25° + cos2 25° = 1.

[∴ cos2 θ + sin2 θ = 1]