Answer:

Step-by-step explanation:
Using the addition formulae for cosine
cos(x ± y) = cosxcosy ∓ sinxsiny
---------------------------------------------------------------
cos(120 + x) = cos120cosx - sin120sinx
= - cos60cosx - sin60sinx
= -
cosx -
sinx
squaring to obtain cos² (120 + x)
=
cos²x +
sinxcosx +
sin²x
--------------------------------------------------------------------
cos(120 - x) = cos120cosx + sin120sinx
= -cos60cosx + sin60sinx
= -
cosx +
sinx
squaring to obtain cos²(120 - x)
=
cos²x -
sinxcosx +
sin²x
--------------------------------------------------------------------------
Putting it all together
cos²x +
cos²x +
sinxcosx +
sin²x +
cos²x -
sinxcosx +
sin²x
= cos²x +
cos²x +
sin²x
=
cos²x +
sin²x
=
(cos²x + sin²x) = 
Answer:
x=111
Step-by-step explanation:
the supplementary angle is 16. triangles should add up to 180.
Answer:
Amplitude is 3
Step-by-step explanation:
in y=-3sin5x
the number in front of sign is always the amplitude. Its not negative 3 because the negative simply means it reflects across the x-axis
Answer:
B
Step-by-step explanation:
Angle 4 × Angle 3 = 90
Complementary angles
11x + 4x = 90
15x = 90
x = 6
Angle 3 = 4x = 4(6) = 24°