JAMB - Mathematics (1994 - No. 31)
What is the value of sin(-690)?
\(\frac{\sqrt{3}}{2}\)
-\(\frac{\sqrt{3}}{2}\)
\(\frac{-1}{2}\)
\(\frac{1}{2}\)
Vysvětlení
Sin(-690o) = Sin(-360 -3300
sin - 360 = sin 0
∴ sin(-690o) = sin(330o)
Negative angles are measured in clockwise direction
The acute angle equivalent of sin(-330o) = sin(30o)
sin(-330o) = sin(30o)
= \(\frac{1}{2}\)
= 0.5
sin - 360 = sin 0
∴ sin(-690o) = sin(330o)
Negative angles are measured in clockwise direction
The acute angle equivalent of sin(-330o) = sin(30o)
sin(-330o) = sin(30o)
= \(\frac{1}{2}\)
= 0.5