ປະເມີນ
-\frac{\sqrt{2}}{2}\approx -0,707106781
ແບ່ງປັນ
ສໍາເນົາຄລິບ
\cos(90+45)=\cos(90)\cos(45)-\sin(45)\sin(90)
Use \cos(x+y)=\cos(x)\cos(y)-\sin(y)\sin(x) where x=90 and y=45 to obtain the result.
0\cos(45)-\sin(45)\sin(90)
Get the value of \cos(90) from trigonometric values table.
0\times \frac{\sqrt{2}}{2}-\sin(45)\sin(90)
Get the value of \cos(45) from trigonometric values table.
0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\sin(90)
Get the value of \sin(45) from trigonometric values table.
0\times \frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}\times 1
Get the value of \sin(90) from trigonometric values table.
-\frac{\sqrt{2}}{2}
ເລີ່ມຄຳນວນ.
ຕົວຢ່າງ
ສະສົມQuadratic
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
ສະສົມເສັ້ນ
y = 3x + 4
Arithmetic
699 * 533
Matrix
\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]
ສະສົມພ້ອມກັນ
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
ຄວາມແຕກແຍກ
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
ການຮວມ
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
ຂີດຈໍາກັດ
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}