# Thread: help pls,math exam

1. ## help pls,math exam

Sin(π/2 + x).sin(π/2-x) =3
Cos(π/4+x).cos(π/4-x)

2. Originally Posted by shadowmist
Sin(π/2 + x).sin(π/2-x) =3
Cos(π/4+x).cos(π/4-x)
Does the above mean the following?

. . . . . $\frac{\sin\left(\frac{\pi}{2}\, +\, x\right)\, \times\, \sin\left(\frac{\pi}{2}\, -\, x\right)}{\cos\left(\frac{\pi}{4}\, +\, x\right)\, \times\, \cos\left(\frac{\pi}{4}\, -\, x\right)}\, =\, 3$

If not, please reply with clarification. For instance, what is the significance in the upper- and lower-case names? What do the decimal points indicate?

Also, what were the instructions? What are you supposed to be doing with this equation? What have you tried so far? Where are you stuck?

Please be complete. Thank you!

3. all right,then.It means what you just wrote.The instructions are simple- just find x.I tried to make somehow sinus into cosinus ,but it didnt work. Hope you can help me.