find sin105°+cos105°
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Answered by
5
sin105 + cos105
= 0.96592582628 + (-0.2588190451)
= 0.965925826- 0.258819045
= 0.707106781
= 0.96592582628 + (-0.2588190451)
= 0.965925826- 0.258819045
= 0.707106781
shivangipandey:
it's not a right answer
Answered by
0
Answer:
1/√2
Step-by-step explanation:
cos(105°) + sin(105°) can be rewritten as:
cos(45° + 60°) + sin(45° + 60°)
now, use the addition identities for cos and sin:
cos(a + b) = cos(a)cos(b) - sin(a)sin(b)
sin(a + b) = sin(a)cos(b) + cos(a)sin(b)
plug in a=45° and b=60° to the identities:
cos(45°)cos(60°) - sin(45°)sin(60°) + sin(45°)cos(60°) + cos(45°)sin(60°)
solve using knowledge of 45–45–90 and 30–60–90 triangles:
(√2)/2 • 1/2 - (√2)/2 • (√3)/2 + (√2)/2 • 1/2 + (√2)/2 • (√3)/2
simplify:
(√2)/4 - (√6)/4 + (√2)/4 + (√6)/4
(√2)/4 + (√2)/4
2(√2)/4
(√2)/2
=1/√2
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