The value of cos(-330°) =
(a)-√3/2
(b)√3/2
(c) 1/2
(d) none of these.
Answers
Answered by
1
Answer:
Remember that
cos
(
a
−
b
)
=
cos
(
a
)
cos
(
b
)
+
sin
(
a
)
sin
(
b
)
and that
330
º
=
360
º
−
30
º
, so
cos
(
330
º
)
=
cos
(
360
º
−
30
º
)
=
cos
(
360
º
)
cos
(
30
º
)
+
sin
(
360
º
)
sin
(
30
º
)
The cosine, sine, tangent and secant of 360º equal the cosine, sine, tangent and secant of 0º respectively. We know that
sin
0
º
is 0, and that
cos
0
º
=
1
so
cos
(
330
º
)
=
1
⋅
cos
(
30
º
)
+
0
⋅
sin
(
30
º
)
cos
(
330
º
)
=
√
3
2
Answered by
0
Answer:
cos(330º)=√32. Explanation: Remember that cos(a−b)=cos(a)cos(b)+sin(a) sin(b) and that 330º=360º−30º , so.
Step-by-step explanation:
The sine, cosine and tangent of negative angles can be defined as well. ... The angle POQ is 30° and is called the related angle for 330°. ... a sin 120° b cos 150° c tan 300° d cos 240°.
ANS--( D )
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