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.
Hello there, and thank you for posting your question here on brainly.
A trapezoid is not possible to have for obtuse because it would look more like a diamond. Also, if it had 4 obtuse angles, it would have 6 sides.
Hope this helped!! ☺♥
Add like terms and then simplify
If the ball hit the ground it means that its height is equal to 0. In order to find the time after the ball <span>will hit the ground, we need to find the solution of the equation h(x)=0 which is different to 0.
-4.9x^2+21.3x=0
x(-4.9x+21.3)=0
-4.9x+21.3=0
x=21.3/4.9 = 4.3469 seconds</span>
(x-4)(x+1)
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