Question
Find the acute angle between the lines whose direction ratios are 5, 12, -13 and 3, -4, 5
$\cos \theta=\left|\frac{a_1 a_2+b_1 b_2+c_1 c_2}{\sqrt{a_1^2+b_1^2+c_1^2} \sqrt{a_2^2+b_2^2+c_2^2}}\right|$
$=\left|\frac{15-48-65}{\sqrt{25+144+169} \sqrt{9+16+25}}\right|$
$=\left|-\frac{98}{13 \sqrt{2} \times 5 \sqrt{2}}\right|$
$=\left|-\frac{98}{13 \times 5 \times 2}\right|$
$=\frac{49}{65}$
$\theta=\cos ^{-1}\left(\frac{49}{65}\right)$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
sin θ – cosθ = 1
|
X:
|
0
|
1
|
2
|
|
P(X):
|
0.6
|
0.4
|
0.2
|