Let R={(x,y):x,yϵZ,y=2x−4}. If (a, -2) and 4,b2)ϵR, then write the values of a and b.
We have,
R = {(x,y):x,yϵZ,y=2x−4}
Now,
y = 2x - 4
Putting y = - 2 and x = a, we get
-2 = 2a - 4
⇒4−2=2a
⇒2=2a
⇒2a=2
⇒a=22=1
Putting y=b2 and x = 4, we get
b2=2×4−4
⇒b2=8−4
⇒b2=4
⇒b=±2
Hence, a=1,b=±2.