A point on the unit circle corresponds to an angle that measures from the positive –axis

MATHEMATICS · Subjective · CBSE · Mathematics · Trigonometric Functions · Trigonometric Functions

Problem

A point

P

on the unit circle corresponds to an angle that measures

45^{\circ}

from the positive

x

–axis. (i) Write the exact coordinates of

P

. (ii) Determine the coordinates of the point that corresponds to an angle of

135^{\circ}

and state clearly how the signs of the

x

– and

y

–coordinates are decided. (iii) Repeat part (ii) for angles

225^{\circ}

and

315^{\circ}

. (iv) Explain briefly why the four points obtained in parts (i)–(iii) can be regarded as reflections of one another about the coordinate axes.