If 2i +pj and 4i -2j are perpendicular, find the value of p.
Answer Details
To find the value of p, we need to use the concept of perpendicular vectors. Two vectors are perpendicular if and only if the dot product of the two vectors is equal to zero.
The dot product of two vectors can be calculated as the product of the magnitudes of the two vectors and the cosine of the angle between them. If the angle between the two vectors is 90 degrees, the cosine of the angle is zero and the dot product is also zero.
Therefore, to find the value of p, we need to calculate the dot product of the two vectors, 2i + pj and 4i - 2j, and set it equal to zero.
The dot product of two vectors (a, b) and (c, d) is given by:
(a, b) * (c, d) = ac + bd
So, the dot product of 2i + pj and 4i - 2j is:
(2i + pj) * (4i - 2j) = (2 * 4) + (p * -2) = 8 - 2p = 0
Therefore, 2p = 8 and p = 4.
So, the value of p is 4.