Question

If ab//cd then the value of r°+s°-t°

Answer 1

a+b=1,——→p

c+d=1,and——→q

a−b=d/c.——→r

Add ‘p’ and ‘r’, and solving for ‘a’ yields

a=(c+d)/2c.

Similarly we get b=(c−d)/2c.

Now from ‘q’, d=1−c;

⇒a=1/2corc=1/2a.

Also d=1−c=(2a−1)/2a.

So c2−d2=(c+d)(c−d)=c−d=1/2a−(2a−1)/2a.

⇒c2−d2=(2−2a)/2a=(1−a)/a.

But 1−a=b⇒c2−d2=b/a

Answer 2

a-b)=d/c

(a+b)=1

so dividing (1) by (2)

(a-b)/(a+b)=d/c

applying componendo and dividendo rule

(a-b+a+b)/(a+b-(a-b))=(d+c)/(c-d)

a/b=1/(c-d)

(c-d)=b/a …………(A)

(c+d)=1 …………….(B)

multiplying both (A) and(B)

c^2-d^2=b/a.1=b/a