1

Is $(\sin 48)/2$ the same as $\sin 24$? Does $(\sin 48)/2$ simplify to $\sin 24$? I appreciate the fact the sine graph is curved, so would this mean that you could not simply divide the $48$ on the end to receive the correct answer.

ASB
  • 3,999

3 Answers3

3

They're different because $(\sin 48)/2 = \sin 24 \cos 24 \neq \sin 24$.

kobe
  • 41,901
  • Right thankyou, that's kind of what I thought, but I thought I'd double check, that being said how would I go about solving 2x=sin48 between a given range? – Toby Cannon Mar 12 '15 at 16:58
  • In what range? The only solution is $x = (\sin 48)/2$. – kobe Mar 12 '15 at 17:00
  • @TobyCannon the equation $2x = \sin 48$ is a linear equation in $x$. It's not a trigonometric equation like $\sin^2 x = \cos x$. – kobe Mar 12 '15 at 17:02
1

Is ${\sin\pi\over 2}=\sin{\pi\over2}$? Is $0=1?$

Fermat
  • 5,230
1

You cannot treat the argument of the sin function as a number you can manipulate with constants outside of the scope of $\sin$.

However, since $\sin(2a) = 2\sin a \cos a$, we have $$\dfrac{\sin(48)}2 = \dfrac{\sin (2(24))}2 = \dfrac{2\sin(24)\cos(24)} 2 = \sin (24)\cos (24)$$

amWhy
  • 209,954