# In which quadrants do cosine and tangent have the opposite sign?

#### Risposta:

bb(III) e bb(IV)

#### Spiegazione:

Starting from the initial side, theta=0 and rotating counter- clockwise through each quadrant, we have:

color(white)(888888888)bbIcolor(white)(8888888)bb(II)color(white)(8888888)bb(III)color(white)(8888888)bb(IV)

bb(cos(theta)color(white)(88)bb(+)color(white)(888.88)-color(white)(888.888)-color(white)(8888.88)+

bb(tan(theta)color(white)(88)bb(+)color(white)(888.88)-color(white)(888.888)+color(white)(8888.88)-

From this we can see that they have opposite signs in quadrants.

bb(III) e bb(IV)