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Mathematics
Mathematics
Problem
Let
θ
\theta
θ
be an acute angle such that
sin
θ
=
3
5
\sin\theta = \dfrac{3}{5}
sin
θ
=
5
3
. (a) Calculate
cos
θ
\cos\theta
cos
θ
. (b) Hence find
tan
θ
\tan\theta
tan
θ
. (c) Evaluate
(
1
+
sin
θ
)
(
1
−
sin
θ
)
(1+\sin\theta)(1-\sin\theta)
(
1
+
sin
θ
)
(
1
−
sin
θ
)
and show that the result equals
cos
2
θ
\cos^{2}\theta
cos
2
θ
for this value of
θ
\theta
θ
.
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