Question

i) cos(-=-x) cos(-y
) – sin(-5--<) sin(-y)
- cos (x+y)​

Answer 1

Answer:

3cosx+5sin(x−

6

π

)

=3cosx+5sinxcos

6

π

−5cosxsin

6

π

=3cosx+

2

5

3

sinx

−

2

5cosx

=

2

cosx

+

2

5

3

sinx

Using −

p

2

+q

2

≤pcosx+qsinx≤

p

2

+q

2

We get

−

19

≤

2

cosx

+

2

5

3

sinx

≤

19

∴(a,b)=(−

19

,

19

)