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Find the value of sin 135.

We have to find the value of sin 135º sin(135) can be expressed as = sin (90 + 45) Using the identity sin(A + B) = sin(A)cos(B) + cos(A)sin(B)... View Article

Six cards and six envelopes are numbered 1, 2, 3, 4, 5, 6 and cards are to be placed in envelopes so that each envelope contains exactly one card and no card is placed in the envelope bearing the same number and moreover the card numbered 1 is always placed in envelope numbered 2. Then the number of ways it can be done is

The number of derrangements of 6 = 6! (1 – 1/1! + 1/2! - 1/3! + 1/4! – 1/5! + 1/6!) = 360 – 120 + 30 – 6 + 1 = 265 Out of these derangements,... View Article