Question

For what values of q are the two vectors A = i + j + kq each other and B-iq-23 + 2kg perpendicular to

Answer 1

Answer:

The value of q are 0.781,-1.281.

Step-by-step explanation:

Given : Two vectors $A=i+j+kq$ and $B=iq-2j+2kq$ are perpendicular to each other.

To find : The value of q ?

Solution :

When two vectors are perpendicular to each other then their dot product is zero.

i.e. $\vec{A}\cdot \vec{B}=0$

Two vectors $A=i+j+kq$ and $B=iq-2j+2kq$

$(i+j+kq)\cdot (iq-2j+2kq)=0$

$(1)(q)+(1)(-2)+(q)(2q)=0$

$q-2+2q^2=0$

$2q^2+q-2=0$

$2q^2+q-2=0$

Using quadratic formula,

$q=\frac{-1\pm\sqrt{1^2-4(2)(-2)}}{2(2)}$

$q=\frac{-1\pm\sqrt{17}}{4}$

$q=\frac{-1+\sqrt{17}}{4},\frac{-1-\sqrt{17}}{4}$

$q=0.781,-1.281$

Therefore, The value of q are 0.781,-1.281.