Answer:
(a+b)^2+(a-b)^2=2(a^2+b^2)
expanding:
a² + 2ab + b² + a² -2ab + b² = 2a² + 2b²
2a² + 2b² = 2a² + 2b²
1 7/10 can be rewritten as 1.7
51 / 1.7 = 30 plants.
<span>Rosalie has 30 plants.
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Draw a diagram to illustrate the problem as shown in the figure below.
Let h the height of the hill. =
At position A, the angle of elevation is 40°, and the horizontal distance to the foot of the hill is x.
By definition,
tan(40°) = h/x h = x tan40 = 0.8391x
(1)
At position B, Joe is (x - 450) ft from the foot of the hill. His angle of elevation is
40 + 18 = 58°.
By definition, tan(58°) = h/(x - 450)
h = (x - 450) tan(58°) = 1.6003(x-450)
h = 1.6003x - 720.135 (2)
Equate (1) and (2).
1.6003x - 720.135 = 0.8391x 0.7612x = 720.135
x = 946.0523
From (1), obtain
h = 0.8391*946.0523 = 793.8 ft
Answer: The height of the hill is approximately 794 ft (nearest integer)