Question

12. The value of cos 15° - sin 15° is equal to
​

Answer 1

1/√2

Step-by-step explanation:

cos 15°= (√3+1)/2√2

sin 15°= (√3-1)/2√2

cos 15°-sin 15°= (√3+1)/2√2 -(√3-1)/2√2

=1/√2

Answer 2

======================================================

$cos(45^o-30^o)-sin(45^o-30^o)\\\\=>cos45^o.cos30^o+sin45^o.sin30^o-(sin45^o.cos30^o-cos45^o.sin30^o)\\\\=>(\frac{1}{\sqrt{2} } .\frac{\sqrt{3} }{2 })+(\frac{1}{\sqrt{2} }.\frac{1}{2})-[(\frac{1}{\sqrt{2} }.\frac{\sqrt{3} }{2} )-(\frac{1}{\sqrt{2} }.\frac{1}{2} )]\\\\=>\frac{\sqrt{3}+1 }{2\sqrt{2} } -[\frac{\sqrt{3}-1 }{2\sqrt{2} } ]\\\\=>\frac{2}{2\sqrt{2} }\\\\ =>\frac{1}{\sqrt{2} }$

======================================================

>>> Hope Helps You <<<

$<marquee>Thank My Answer If It Helps </marquee>$