Question

show that :(p-q-r)²=p²+q²+r²+2pq+2qr-2rp
solve it properly using suitable identity

ans:((p-q)-r)²
we know that: (a-b)²=(a²-2ab+b²)
((p-q)-r)²=[(p-q²)-2(p-q)(r)(r)²]
solve after this​

Answer 1

Answer:

Here (p-q-r)² = ( a-b-c)²

( a-b-c)² = -2ab-2ac+a²+b²+2bc+c²

hence (p-q-r)² = -2pq-2pr+p²+q²+2qr+r²