find the value of Sin (75°).
Hence, find cos (15°)
Answers
Answer:
Sin 75 = Sin(45+30)…………………..(1)
By applying the formula
Sin (A + B) = Sin A. Cos B + Cos A. Sin B
Sin (45 + 30) = Sin 45. Cos 30 + Cos 45. Sin 30…………………..(2)
Sin Values
sin 0° = √(0/4) = 0
sin 30° = √(1/4) = ½
sin 45° = √(2/4) = 1/√2
sin 60° = √3/4 = √3/2
cos 90° = √(4/4) = 1
Cos Values
cos 0° = √(4/4) = 1
cos 30° = √(3/4) = √3/2
cos 45° = √(2/4) = 1/√2
cos 60° = √(1/4) = 1/2
cos 90° = √(0/4) = 0
Substitute the value of sin 30, sin 45, cos 30 and cos 45 degrees, then equation (2) will becomes
Sin (45 + 30) = Sin 45. Cos 30 + Cos 45. Sin 30
Sin (45 + 30) = 1/√2 . √3/2 + 1/√2 . 1/2
Sin (45 + 30) = (√3 + 1) / 2√2
Hence the value of Sin 75 degree is equal to
(√3 + 1) / 2√2.
Cos15 = Cos(45–30)…………………..(1)
By applying the formula
Cos (A – B) = Cos A. Cos B + Sin A. Sin B
Cos (45 – 30) = Cos 45. Cos 30 + Sin 45. Sin 30…………………..(2)
Sin Values
sin 0° = √(0/4) = 0
sin 30° = √(1/4) = ½
sin 45° = √(2/4) = 1/√2
sin 60° = √3/4 = √3/2
cos 90° = √(4/4) = 1
Cos Values
cos 0° = √(4/4) = 1
cos 30° = √(3/4) = √3/2
cos 45° = √(2/4) = 1/√2
cos 60° = √(1/4) = 1/2
cos 90° = √(0/4) = 0
Substitute the value of sin 30, sin 45, cos 30 and cos 45 degrees, then equation (2) will becomes
Cos (45 – 30) = 1/√2 . √3/2 + 1/√2 . 1/2
Cos 15 = √3/2√2 + 1/2√2
Cos 15 = √3+1/2√2
Step-by-step explanation:
I am confused in equation 4 th
please classify the assets, libilites, and capital
my answer getting wrong so please tell me