Jawab:

trigonometri
fungsi

Diketahui cos a = 6/10 (a sudut lancip).

cos a = 6/10 = 3/5 =s/m

s= 3 , m = 5 ,

d = √m²-s²

d = √5²-3² = √16

d= 4

sin a =  d/m = 4/5
tan a =  d/s = 4/3

Hitunglah nilai dari:

a. sin a cos a + cos a sin a =

=  4/5 x 3/5  + 3/5 x 4/5
= 12/25 + 12/25
= 24/25

b. cos a cos a - sin a sin a,

= 3/5 x  3/5  -  4/5 . 4/5
=  9/25 - 16/25

= - 7/25

c. tan a tan a - sin a sin a,

=  4/3 x 4/3 -  4/5 x 4/5

= 16/9 - 16/25

= 256/225

d. cos a tan a + tan a sin a!

=  3/5 x  4/3  +  4/3 x 4/5

= 12/15 + 16/15

= 28/15