Step-by-step explanation:
the slope of a line is always the factor of x.
here : 1/2
it is the ratio y/x indicating how many units y changes, when x changes a certain angina amount of units when going from one point to another.
a perpendicular slope puts x and y upside-down and flips the sign.
here : -2/1 = -2
so, the equation looks like
y = -2x + b
b is the y-intercept, and we get this by putting the x and y coordinates of the given point into this equation and solve for b :
-1 = -2×-2 + b
-1 = 4 + b
b = -5
the full equation is therefore
y = -2x - 5
Answer:
Height of the goalpost is 9.25 m.
Step-by-step explanation:
As per the rule of reflection in physics,
Angle of incidence = Angle of reflection
As we can see in the picture attached, both the angles (θ) are equal.
m∠ACB = m∠ECD = 90° - θ
m∠ABC = m∠ADC = 90°
Therefore, both the triangles ΔABC and ΔEDC will be similar.
And by the property of similar triangles, their corresponding sides will be proportional.


ED = 
ED = 9.25 m
Height of the goalpost is 9.25 m.
Here are the answers: they are in red
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.