Question
If sin A - cos A = 3/7, then find value of sinA + cos
B, where A is an acute angle.Solution
We Know that, (a+b)2 + (a-b)2 = 2(a2 + b2) Hence, (sin A + cos A)2 +
= 2(sin2 A + cos2 A) => (sin A + cos A)2Â +Â
 = 2(1) => (sin A + cos A)2  = 2 -Â
=> (sin A + cos A)2Â Â = 2 -
=
=
=> (sin A + cos A)Â =
Find the wrong number in given number series.
1960, 1943, 1930, 1915, 1904, 1895
180000, 7200, 360, 36, 2.4, 0.48
33Â Â Â Â 34Â Â Â 37Â Â Â 42Â Â Â 48Â Â Â 58
54Â Â Â Â 54Â Â Â Â Â 108Â Â Â Â 39Â Â Â Â 144Â Â Â Â 28.8
1677, 1661, 1625, 1561, 1461, 1337.
124, 186, 375, 930, 2790, 9765
Find the wrong number in the given number series.
20, 33, 50, 69, 93, 121
Find the wrong number in the given number series.
934, 885, 949, 868, 968, 849Â
- 80, - 44, - 4, 88, 216, 380
In each of the following number series, one term is wrong. Find the wrong term.
4, 7, 12, 21, 28, 39, 52