Answer:
Step-by-step explanation:
Numerator
sin
x
cos
y
+
cos
x
sin
y
−
[
sin
x
cos
y
−
cos
x
sin
y
)
=
sin
x
cos
y
+
cos
x
sin
y
−
sin
x
cos
y
+
cos
x
sin
y
=
2
cos
x
sin
y
Denominator
cos
x
cos
y
−
sin
x
sin
y
+
cos
x
cos
y
+
sin
x
sin
y
=
cos
x
cos
y
−
sin
x
sin
y
+
cos
x
cos
y
+
sin
x
sin
y
=
2
cos
x
cos
y
---------------------------------------------------------------
left side can now be expressed as
2
cos
x
sin
y
2
cos
x
cos
y
=
2
cos
x
sin
y
2
cos
x
cos
y
=
sin
y
cos
y
and
sin
y
cos
y
=
tan
y
=
right side hence proved
Answer:
Step-by-step explanation:
Given that:
sin2xcos x + cos2xsin x = -1
Recall that;
SInAcosB + cosASinB = SIn (A+B)
SIn (2x +x) = -1
Sin (3x) = -1
![x = \bigg [\dfrac{Sin ^{-1} (-1)}{3} \bigg ]](https://tex.z-dn.net/?f=x%20%3D%20%5Cbigg%20%5B%5Cdfrac%7BSin%20%5E%7B-1%7D%20%28-1%29%7D%7B3%7D%20%20%5Cbigg%20%5D)


Answer:
7 track practices.
Step-by-step explanation:
36 miles - 8 miles she already ran= 28 miles left to run.
28 divided by 4 (miles) = 7.