Answer:
[tex] \frac{20}{29}[/tex]
Step-by-step explanation:
Equation of unit circle is:
[tex] x^2 + y^2 = 1[/tex]
Plug [tex] y = \frac{-21}{29}[/tex] in above equation.
[tex] x^2 + \bigg( \frac{-21}{29}\bigg)^2 = 1\\\\
x^2 + \frac{441}{841} = 1\\\\
x^2 = 1-\frac{441}{841}\\\\
x^2 = \frac{841-441}{841}\\\\
x^2 = \frac{400}{841}\\\\
x =\pm\sqrt{ \frac{400}{841}}\\\\
x =\pm\frac{20}{29}\\\\
[/tex]
Since, point P is in the fourth quadrant.
Therefore, x - coordinate should be positive.
[tex] \huge \red {\boxed {\therefore x =\frac{20}{29}}} \\\\
[/tex]
