Find the value of : (i) `sin75^o` (ii) `tan15^o`

Explanation

(i) `sin 75^@ = sin(45^@ + 30^@)`

using identity `sin(a+b) = sinacosb + cosasinb`

`= sin45^@cos30^@ + cos45^@sin30^@`

`= 1/sqrt2 * sqrt3/2 + 1/sqrt2 * 1/2 `

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

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

(ii) `tan 15^@ = tan(45^@- 30^@)`

using identity `tan(a-b) = (tana- tanb)/(1+tan a tan b)`

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