Answer:
D
Step-by-step explanation:
Parallel lines have the same gradient.
A line with a slope of zero is a horizontal line. Although two lines that have a slope of zero will result in two parallel lines, not all parallel lines are horizontal lines. Since the question is asking for which statement <u>must</u> be true, option A is incorrect.
If the slopes of two lines are negative reciprocals, they are perpendicular to each other. This is because the product of the gradients of 2 perpendicular lines is -1. Let the gradient of the first line be A and the other be B.
AB= -1
Thus, option B is incorrect too.
Undefined slopes gives vertical lines. Like option A, if two lines have an undefined slope, they will be parallel to each other. However since parallel lines are nit necessarily vertical lines, option C is also incorrect.
Quick answer I don't think this has an answer.
If you take the cos-1(2 sqrt(2)) your calculator should have a fit. Let's check that out. Mine certainly does. So there is something wrong with the question. If there is something to add in please do it and I will it least put an answer in the comments. As it stands, nothing will work.
If you put your calculator in radians, you will get an answer but it will not be anything resembling the choices you've listed.
If you meant sqrt(2) / 2 that would give 45o. Put it in your calculator like this 2 ^ 0.5 divided by 2 = 0.707
Cos - 1 (0.707) = 45
Answer:
7.7 repeated
Step-by-step explanation:
3 1/3 * 2 1/3 = 7.7 repeated
Answer:
x = 28
Step-by-step explanation:
Given that lines AB and CD are straight lines that intersects at O, it follows that the pair of opposite vertical angles formed are congruent.
Thus,
<AOD = <BOC
<AOD = 152°
<BOC = 3x + x + (x + 12) (angle addition postulate)
<BOC = 5x + 12
Since <AOD = <BOC, therefore,
152° = 5x + 12 (substitution)
152 - 12 = 5x (subtraction property of equality)
140 = 5x
140/5 = x (division property of equality)
28 = x
x = 28
