NTA Abhyas 2020
- Exam
- NTA Abhyas
- Year
- 2020
- Subject
- Mathematics
- Chapter
- Trigonometric Equations
NTA Abhyas 2020 · Mathematics · Trigonometric Equations
The equation kcos x - 3sin x = k + 1 is solvable only if
The equation is solvable only if
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
kcos x - 3sin x = k + 1⇒ \left|k + 1\right|\le \sqrt{k^{2} + 9}k^{2} + 1 + 2k \le k^{2} + 9⇒ 2k \le 8 ⇒ k \le 4⇒ k \in \left(- \infty,4\right]