Luacháil
\frac{\sqrt{2}}{2}\approx 0.707106781
Tráth na gCeist
Trigonometry
\cos ( \frac { 7 \pi } { 4 } )
Roinn
Cóipeáladh go dtí an ghearrthaisce
\cos(\frac{3\pi }{2}+\frac{\pi }{4})=\cos(\frac{3\pi }{2})\cos(\frac{\pi }{4})-\sin(\frac{\pi }{4})\sin(\frac{3\pi }{2})
Bain úsáid as \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) nuair atá x=\frac{3\pi }{2} agus y=\frac{\pi }{4}ann chun an toradh a fháil.
0\cos(\frac{\pi }{4})-\sin(\frac{\pi }{4})\sin(\frac{3\pi }{2})
Faigh luach do\cos(\frac{3\pi }{2})ón dtábla luachanna triantánúla.
0\times \frac{\sqrt{2}}{2}-\sin(\frac{\pi }{4})\sin(\frac{3\pi }{2})
Faigh luach do\cos(\frac{\pi }{4})ón dtábla luachanna triantánúla.
0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\sin(\frac{3\pi }{2})
Faigh luach do\sin(\frac{\pi }{4})ón dtábla luachanna triantánúla.
0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\left(-1\right)
Faigh luach do\sin(\frac{3\pi }{2})ón dtábla luachanna triantánúla.
\frac{\sqrt{2}}{2}
Déan áirimh.
Samplaí
Cothromóid chearnach
{ x } ^ { 2 } - 4 x - 5 = 0
Triantánacht
4 \sin \theta \cos \theta = 2 \sin \theta
Cothromóid líneach
y = 3x + 4
Uimhríocht
699 * 533
Maitrís
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Cothromóid chomhuaineach
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Difreáil
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Comhtháthú
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Teorainneacha
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}