If tan θ = 5/4, find sin2θ - cos2θ.
A
5/4
B
41/9
C
9/41
D
1
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Tan θ = 5/4
x2 = 52 + 42
= 25 + 16
= 41
x = √41
sin2θ - cos2θ = (5/√41)2 - (4/√41)2
= 25/41 - 16/41
= 9/41
Source: Myschool Past Questions Archive (Record #8834)