If 3sec
4
θ+8=10sec
2
θ, then the value of tanθ can be:
- A2
,
3
- B1,
3
- C2
,
3
1
- D1,
3
1
Solution & Step-by-step Explanation
Let sec
2
θ=x. The given equation becomes:
3x
2
−10x+8=0
Let's solve this quadratic equation:
3x
2
−6x−4x+8=0
3x(x−2)−4(x−2)=0
(3x−4)(x−2)=0
This gives two possible values for x:
x=2⟹sec
2
θ=2
x=
3
4
⟹sec
2
θ=
3
4
We know the trigonometric identity: tan
2
θ=sec
2
θ−1.
Case 1: tan
2
θ=2−1=1⟹tanθ=1
Case 2: tan
2
θ=
3
4
−1=
3
1
⟹tanθ=
3
1
Thus, tanθ can be 1 or
3
1
.
2
θ=x. The given equation becomes:
3x
2
−10x+8=0
Let's solve this quadratic equation:
3x
2
−6x−4x+8=0
3x(x−2)−4(x−2)=0
(3x−4)(x−2)=0
This gives two possible values for x:
x=2⟹sec
2
θ=2
x=
3
4
⟹sec
2
θ=
3
4
We know the trigonometric identity: tan
2
θ=sec
2
θ−1.
Case 1: tan
2
θ=2−1=1⟹tanθ=1
Case 2: tan
2
θ=
3
4
−1=
3
1
⟹tanθ=
3
1
Thus, tanθ can be 1 or
3
1
.