Practicing Success
Find the value of cos 9°+sin 9°. |
sin 54° \(\sqrt {2}\)cos 54° \(\sqrt {2}\)sin 54° 0 |
\(\sqrt {2}\)sin 54° |
Divide & Multiply the eq. by \(\sqrt{2}\) \(\frac{\sqrt{2}}{\sqrt{2}}\) (cos 9°+sin 9°) Sin(A+B) = sinA cosB + cosAsinB \(\sqrt{2}\left(\frac{1}{\sqrt{2}} \cos 9^{\circ}+\frac{1}{\sqrt{2}} \sin 9^{\circ}\right) \) \(\sqrt{2}\left(\sin 45^{\circ} \cos 9^{\circ}+\cos 45^{\circ} \sin 9^{\circ}\right) \) \(\sqrt{2}(\sin (45+9)) \) \(\sqrt{2} \sin 54^{\circ}\) |