Question

The value of cos 10º – sin 10° is​

Answer 1

Answer:

( sqrt 2) × sin35

Step-by-step explanation:

This is related to trigonometric transformations

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We know that ,

i ) cos ( 90 - A ) = sin A

ii ) sin C - Sin D = 2cos( C + D )/2 × sin(C - D )/2

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Cos 10 - sin 10

= cos (90-80) - sin10

= sin80 - sin10

= 2cos(80+10)/2×sin(80-10)/2

= 2cos45sin35

= 2 × ( 1/sqrt2) sin35

= ( sqrt2 × sqrt2 )/ ( sqrt2 ) × sin35

= ( sqrt 2) × sin35

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Answer 2

Answer:

cos square10+sinsquare10=1

Step-by-step explanation:

then

(cos10°+sin10°)(cos10°-sin10°)

we have,

(cos10°-sin10°)=1/(cos10°+sin10°)