Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
In a right-angled triangle
A
B
C
ABC
A
B
C
, right-angled at
C
C
C
, let
∠
A
=
θ
\angle A=\theta
∠
A
=
θ
and
∠
B
=
90
∘
−
θ
\angle B=90^{\circ}-\theta
∠
B
=
9
0
∘
−
θ
. a. (i) If
sin
θ
=
5
13
\sin\theta=\dfrac{5}{13}
sin
θ
=
13
5
, find
cos
(
90
∘
−
θ
)
\cos(90^{\circ}-\theta)
cos
(
9
0
∘
−
θ
)
. b. (ii) Using the result of part (i), determine
sec
(
90
∘
−
θ
)
\sec(90^{\circ}-\theta)
sec
(
9
0
∘
−
θ
)
. c. (iii) Hence, calculate the value of
sin
θ
+
cos
(
90
∘
−
θ
)
tan
(
90
∘
−
θ
)
\dfrac{\sin\theta+\cos(90^{\circ}-\theta)}{\tan(90^{\circ}-\theta)}
tan
(
9
0
∘
−
θ
)
sin
θ
+
cos
(
9
0
∘
−
θ
)
.
Browse the problem library