Question

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Answer 1

Answer:

c) sin (40+x)cos (10+x)-cos(40+x)sin(10+x)=1/2

we know

sinAcosB-cosAsinB=sin(A-B)

then, the upper equation is

sin(40+x-10-x)

=sin 30

=1/2(proved)

b)sin x=12/13

cos 2x

=cos^2x-sin^2x

=1-sin^2x-sin^2x

=1-2sin^2x

=1-2.(12/13)^2

=1-2.144/169

=1-288/169

=(169-288)/169

= -119/169

a)20°40'into radian

we know,

180°=π radian

20°40'=20°40/60°=20 2/3°=62/3°

62/3°=π×62/3×180°=62π/540°

Answer 2

Answer:

ali moti sanai

Step-by-step explanation:

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