Joseph and Chandra are cleaning their house which has 12 rooms, each about the same size. If Joseph cleans them by himself, it t
2 answers:
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Answer: The lines L1 and L2 are parallel.
Step-by-step explanation: We are given to determine whether the following lines L1 and L2 passing through the pair of points are parallel, perpendicular or neither :
L1 : (–5, –5), (4, 6),
L2 : (–9, 8), (–18, –3).
We know that a pair of lines are
(i) PARALLEL if the slopes of both the lines are equal.
(II) PERPENDICULAR if the product of the slopes of the lines is -1.
The SLOPE of a straight line passing through the points (a, b) and (c, d) is given by
So, the slope of line L1 is
and
the slope of line L2 is
Therefore, we get
Hence, the lines L1 and L2 are parallel.
Solution:
As we know reference angle is smallest angle between terminal side and X axis.
As cosine 45 ° is always positive in first and fourth quadrant.
i.e CosФ, Cos (-Ф) or Cos(2π - Ф) have same value.
As, Cos 45°, Cos (-45°) or Cos ( 360° - 45°)= Cos 315°are same.
So, Angles that share the same Cosine value as Cos 45° have same terminal sides will be in Quadrant IV having value Either Cos (-45°) or Cos (315°).
Also, Cos 45° = Sin 45° or Sin 135° i.e terminal side in first Quadrant or second Quadrant.
