$$$\left[\begin{array}{cc}2 \cos{\left(5 v \right)} & - 10 u \sin{\left(5 v \right)}\\0 & 10 \cos{\left(5 v \right)}\end{array}\right]$$$:n determinantti
Aiheeseen liittyvä laskin: Kofaktorimatriisilaskin
Syötteesi
Laske $$$\left|\begin{array}{cc}2 \cos{\left(5 v \right)} & - 10 u \sin{\left(5 v \right)}\\0 & 10 \cos{\left(5 v \right)}\end{array}\right|$$$.
Ratkaisu
2x2-matriisin determinantti on $$$\left|\begin{array}{cc}a & b\\c & d\end{array}\right| = a d - b c$$$.
$$$\left|\begin{array}{cc}2 \cos{\left(5 v \right)} & - 10 u \sin{\left(5 v \right)}\\0 & 10 \cos{\left(5 v \right)}\end{array}\right| = \left(2 \cos{\left(5 v \right)}\right)\cdot \left(10 \cos{\left(5 v \right)}\right) - \left(- 10 u \sin{\left(5 v \right)}\right)\cdot \left(0\right) = 20 \cos^{2}{\left(5 v \right)}$$$
Vastaus
$$$\left|\begin{array}{cc}2 \cos{\left(5 v \right)} & - 10 u \sin{\left(5 v \right)}\\0 & 10 \cos{\left(5 v \right)}\end{array}\right| = 20 \cos^{2}{\left(5 v \right)}$$$A