A
B
Simple harmonic with amplitude ab
C
Simple harmonic with amplitude a2+b2
D
Simple harmonic with amplitude (a+b)2
The two displacement equations are y1 = a sin(ωt) and y2 = b cos(ωt) = b sin(ωt+π2)
yeq = y1+y2
= a sin ωt + b cos ωt
= a sin ωt + b sin (ωt+π2)
Since the frequencies for both SHMs are same, resultant motion will be SHM.
Now Aeq = a2+b2+2abcosπ2
⇒Aeq = a2+b2