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Evaluate the Following Sin 45° Sin 30° + Cos 45° Cos 30°

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प्रश्न

Evaluate the following

sin 45° sin 30° + cos 45° cos 30°

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उत्तर

sin 45° sin 30° + cos 45° cos 30° …...(i)

We know that by trigonometric ratios we have,

`sin 45^@ = 1/sqrt2   sin 30^@ = 1/2`

`cos 45^@ = 1/sqrt2    cos 30^@ = sqrt3/2`

Substituting the values in (i) we get

`1/sqrt2 . 1/2 + 1/sqrt2 . sqrt3/2`

`= 1/sqrt2 . sqrt3/(2sqrt2) = (sqrt3 + 1)/(2sqrt2)`

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अध्याय 10: Trigonometric Ratios - Exercise 10.2 [पृष्ठ ४१]

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आर.डी. शर्मा Mathematics [English] Class 10
अध्याय 10 Trigonometric Ratios
Exercise 10.2 | Q 1 | पृष्ठ ४१

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