Verified below
Explanation:
cot
B
sec
B
β
tan
B
β
cos
B
sec
B
+
tan
B
=
sin
B
+
csc
B
A common denominator to add these fractions:
cot
B
(
sec
B
+
tan
B
)
(
sec
B
β
tan
B
)
(
sec
B
+
tan
B
)
β
cos
B
(
sec
B
β
tan
B
)
(
sec
B
+
tan
B
)
(
sec
B
β
tan
B
)
=
sin
B
+
csc
B
cot
B
β
sec
B
+
cot
B
β
tan
B
sec
2
B
β
tan
2
B
β
cos
B
β
sec
B
β
cos
B
β
tan
B
sec
2
B
β
tan
2
B
Before we combine let's apply one Pythagorean identity:
1
+
tan
2
x
=
sec
2
x
Manipulated to:
1
=
sec
2
x
β
tan
2
x
That should look familiar as
sec
2
x
β
tan
2
x
is our denominator, so let's substitute a 1 in there:
cot
B
β
sec
B
+
cot
B
β
tan
B
1
β
cos
B
β
sec
B
β
cos
B
β
tan
B
1
There's still one more step before we combine, we need to utilize reciprocal and quotient identities to make the expression simpler:
tan
x
=
sin
x
cos
x
cot
x
=
1
tan
x
sec
x
=
1
cos
x
cot
x
=
cos
x
sin
x
1
sin
x
=
csc
x
So:
cos
B
sin
B
β
1
cos
B
+
1
tan
B
β
tan
B
1
β
cos
B
β
1
cos
B
β
cos
B
β
sin
B
cos
B
1
Leaves us with:
csc
B
+
1
β
(
1
β
sin
B
)
Distribute the negative:
csc
B
+
1
β
1
+
sin
B
Gets us to:
sin
B
+
csc
B