1
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $$\left|\begin{array}{lll}x & x^2 & 1+x^3 \\ y & y^2 & 1+y^3 \\ z & z^2 & 1+z^3\end{array}\right|=0$$ and $$x, y$$ and $$z$$ are all distinct, then $$x y z$$ is equal to

A
$$-$$1
B
1
C
0
D
3
2
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

Let A be a $$n\times n$$ matrix such that A is upper-triangular. Then, $$adj (A)$$ is equal to

A
lower triangular matrix
B
upper triangular matrix
C
diagonal matrix
D
scalar matrix
3
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

Let $$Z_1, Z_2$$ and $$Z_3$$ be three non zero complex numbers such that $$a=\left|Z_1\right|, b=\left|Z_2\right|$$ and $$c=\left|Z_3\right|$$, if the determinant $$\left|\begin{array}{lll}a & b & c \\ b & c & a \\ c & a & b\end{array}\right|=0$$, then

A
$$\left|Z_1\right|=\left|Z_2\right|=\left|Z_3\right|=a b c$$
B
$$\left|Z_1\right|+\left|Z_2\right|+\left|Z_3\right|=0$$
C
$$\left|Z_1\right|+\left|Z_2\right|+\left|Z_3\right|=a b c$$
D
$$\left|Z_1-Z_2\right|=\left|Z_2-Z_3\right|$$
4
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $$\left|z_1+z_2\right|^2=\left|z_1\right|^2+\left|z_2\right|^2$$, where $$z_1$$ and $$z_2$$ are two complex numbers, then

A
$$\frac{z_1}{z_2}$$ is purely real
B
$$\frac{z_1}{z_2}$$ is purely imaginary
C
$$\arg \left(\frac{z_1}{z_2}\right)=\frac{\pi}{4}$$
D
$$\left|\frac{z_1}{z_2}\right|=1$$