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:
11.59x² -7.66x + 9.85
Step-by-step explanation:
3.63x² - 4.54x + 7.96x² +9.85 -3.12x
11.59x² -7.66x + 9.85
Surface area of cone is a sum of surface of its base and surface of its mantle.
Surface of its base is a circle which surface we will calculate like this:
Sb = pi*r^2 where r is d/2
Sb = 201m^2
Surface of mantle we calculate by:
Sm = pi*l*r where l is length of side of cone.
l =

= 25.3
Sm = 635.8m^2
Total suface is:
Sb + Sm = 836.8m^2
Translation rotation reflection