Question

$\cos(15 ) - \tan(30)$
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Answer 1

Hey mate

We know that cos(A-B)=cosAcosB+SinAsinB

Cos15°=Cos(45-30)°

cos45cos30+sin45sin30

(1/√2)*(√3/2)+(1/√2)*(1/2)

= (√3) + 1

2√2. 2√2

=√3+1

2√2

Tan30°= 1/√3

so

=√3+1 + 1

2√2 √3

=(√3+1)√3 + 2√2

2√2*√3

=3+√3+2√2

2√6

Thank you

Regards ☺