Question

HEYA.
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PLZ ANSWER... ALL FOUR

»»29 POINTS..........

Answer 1

question 17 as applying the formula of cos2A
cos(2×15)=. cos30degree


✓3/2

option c is correct

Answer 2

For Answer 15 : see pic 2
For Answer : 16 see pic 3 then see pic 1.
For Answer 17,18 see pic 1

Final Answer :
15 : B)
$\frac{2 - {k}^{2} }{k}$
16: B)
${a}^{2} + {b}^{2} - 3$
17: C)
$\frac{ \sqrt{3} }{2}$
18:D) 0 or Independent ofΦ

For Calculation See Pic.
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