Answer:
11
Step-by-step explanation:
w
Answer:
-117
Step-by-step explanation:
So, basically all you have to do is use the absolute values in order to use order of operations and simplify it along with the multiplied grouping.
Hope this helps :)
Given:
To find:
The obtuse angle between the given pair of straight lines.
Solution:
The slope intercept form of a line is
...(i)
where, m is slope and b is y-intercept.
The given equations are
On comparing these equations with (i), we get
Angle between two lines whose slopes are 
is
Putting and , we get
Now,
and 
and 
and 
, so it is an obtuse angle and 
, so it is an acute angle.
Therefore, the obtuse angle between the given pair of straight lines is 120°.
If you are multiplying fractions it doesn't matter if there are different denominators because you multiply straight across.
Let cos x = a, then
2a^2 + a - 1 = 0,
solving the quadratic equation, we have:
a = 0.5 or -1.
i.e. cos x = 0.5 or cos x = -1
for cos x = 0.5,
x = pi/3, 2pi - pi/3 = pi/3, 5pi/3
for cos x = -1,
x = pi
therefore, x = pi, pi/3, 5pi/3
Answer: B
