180°
90°
45°
0°
Correct answer is B
a.b=|a||b|cosθ
cosθ=a.b|a||b|
= (5i+3j).(3i−5j)(√52+32)(√32+(−5)2)
= 034=0
\theta = \cos^{-1} 0 = 90°
If \frac{^{n}C_{3}}{^{n}P_{2}} = 1, find the value of n....
If \alpha and \beta are the roots of 2x^{2} - 5x + 6 = 0, find the equation whose roots ...
Determine the coefficient of x^{2} in the expansion of (a + 3x)^{6}...
If ^{3x}C_{2} = 15, find the value of x?...
Using binomial expansion of ( 1 + x)^6 = 1 + 6x + 15x^2 + 20x^3 + 6x^5 + x)^6, f...
A particle is acted upon by two forces 6N and 3N inclined at an angle of 120° to each other. Fin...
The polynomial 2x^{3} + x^{2} - 3x + p has a remainder of 20 when divided by (x - 2). Find the v...