Question

The magnitude of two vectors P and Q differ by 1. The magnitude of their resultant makes an angle of tan^-1 (3/4) with P. What will be the angle between P and Q?

Answer 1

it is 90° because think of a right angled triangle formed by sides 3 and 4....and hypotenuse 5..now what tan * becomes....3/4 right....

Answer 2

Answer:

If the value of tan = 3/4 then the value of perpendicular(p) is 3 and the value of base(b) is 3 + 1 = 4 according to the question hence the value of hypotenuse will be $\sqrt{3^2+4^2}$ which is 5.

Now, to find the angle between p and q we have to use the formulae of triangle law of vector.

5^2 = $\sqrt{p^2+q^2+2pqcosx}$  where x is the angle between  P and Q.

25 = 25 + 2pqcosx.

cosx=0.

x=90.