Question
If sin x + sin y = a and cos x + cos y = b, find sin(x +
y):Solution
Using sum-to-product identities: sin x + sin y = 2sin((x + y)/2)cos((x - y)/2), cos x + cos y = 2cos((x + y)/2)cos((x - y)/2). Dividing and simplifying, we get: sin(x + y) = a² + b² - 1. Correct option: b
729 512 343 216 125 ?
...11 28 47 70 ? 130
...In the question, three series I, II and III are given. Find the value of x, y and z to establish the correct relation among them and choose the correct...
108 329 ? 2975 8928 26789 .
5, 8, 17, ?, 37, 48
5 13 36 145 719 4321
130 155 146 195 186 ?
...If 7 43 x 1311 5247 15739
Then, x - x/2 + 2 = ?
...40 42 87 266 ? 5366
3 5 ? 75 1125 84375
...
