Saved Bookmarks
| 1. |
The number of solution of equation `tanx+secx=2cosx` lying in the interval `[-pi,3pi]` is |
|
Answer» Correct Answer - 4 Now `tanx+secx=2cosx` `implies(sinx)/(cosx)+(1)/(cosx)=2cosximpliesinx+1=2cos^(2)x` `impliessinx+1=2(1-sin^(2)x)` `implies2sin^(2)x+sinx-1=0` `implies(1+sinx)(2sinx-1)=0` `impliessinx=(1)/(2),sinx=-1` but `sinx=-1` does not satisfy the equation `x=(pi)/(6),(5pi)/(6),2pi+(pi)/(6),3pi-(pi)/(6)` in `[-pi,3pi]` |
|