Question
Find all solutions of the equation in the interval [0,2pi ) -4cosx=-sin^2x+1 Write your answer in radians in terms of pi If there is more than one solution separate them with commas. x=[ ]
Solution
4.5
(155 Votos)
Elvira
Elite · Tutor por 8 anos
Resposta
To solve the equation
in the interval \([0, 2\pi)\), we can follow these steps:1. Rewrite the equation:
2. Use the Pythagorean identity
to express
in terms of
:
3. Substitute
into the equation:
4. Square both sides to eliminate the square root:
5. Multiply both sides by 16 to clear the fraction:
6. Expand the right-hand side:
7. Rearrange the equation to form a quadratic in
:
8. Let
, then the equation becomes:
9. Solve the quadratic equation using the quadratic formula
:
10. Since
must be in the interval
, we need to check which solutions are valid:
Only
is in the interval
.11. Find
from
:
12. Determine the corresponding
values in the interval \([0, 2\pi)\):
Thus, the solutions in radians in terms of
are: