"Like if I have 5 tshirts and i want to gift them to my 5 cousins named A,B,C,D,E, so find number of ways in which particular cousin won't get their particular tshirts."
So number of ways:
D(n)=n!*(1-1/1!+1/2!-1/3!+.....(-1)^n*1/n!))
Where...
Solution 1: Apply cos c = (17^2 + 4^2 - 15^2)/2*17*4 = 10/17 in ADC.
In ABC, cos C = ( 17^2 + (4+x)^2 - 17^2) / 2*17*(4+x)
Find x.
Find the angle cos C, then take BD as x.
Then cos C will be same for...
Complex Number
Algebra of complex numbers, addition, multiplication, conjugation.
Polar representation, properties of modulus and principal argument.
Triangle inequality, cube roots of...