The number of real values of a satisfying the equation a2−2a sinx+1=0 is
Zero
One
Two
Inifnite
Given equations a2−2asinx+1=0
a=2sinx±2√4sin2x−42 = sinx±2√−(1−sin2x)
a=sinx±icosx
If x=π2 ⇒ a=1, x=270o ⇒ a=-1.