" 14."4r^(2)s^(2)-12pqrs+9p^(2)q^(2)

Factorise the expressions - p^(2)q - pqr^(2) - pqr +p^(2)qr^(2)

If p = -2, q = - 1 and r = 3, find the value of (i) p^(2) + q^(2) - r^(2) (ii) 2p^(2) - q^(2) + 3r^(2) (iii) p - q - r (iv) p^(3) + q^(3) + r^(3) + 3 pqr (v) 3p^(2) q + 5pq^(2) + 2 pqr (vi) p^(4) + q^(4) - r^(4)

If cos^(-1)p+cos^(-1)q+cos^(-1)r=pi then p^(2)+q^(2)+r^(2)+2pqr =

If cos^(-1)p+cos^(-1)q+cos^(-1)r=3pi , then p^(2)+q^(2)+r^(2)+2pqr is equal to

Factoris the expression. 3pqr - 6p^(2) q ^(2) r ^(2) - 15 r ^(2)