Answer:
The statement is false
Step-by-step explanation:
we know that

The tangent function will be positive when the sine function and the cosine function have the same sign
so
In the first quadrant the tangent function is positive
In the third quadrant the tangent function is positive
so
The statement is false
Answer:
Amount of 5% solution = 5.7 Litres
Amount of 40% solution = 4.3 Litres
Step-by-step explanation:
First, of all, let x be the amount of 5% solution used
Since, the scientist needs 10 L of solution, then;
Let 10 - x be the amount of 40% solution used
Now, we are told that she needs 10 L of a 20% acid solution.
This means that;
5%x + 40%(10 - x) = 20%(10).
Simplifying this gives;
0.05x + 0.40(10 - x) = 0.20 × 10
Expanding the bracket gives;
0.05x + 4 - 0.4x = 2
0.4x - 0.05x = 4 - 2
0.35x = 2
x = 2/0.35
x ≈ 5.7 litres
Thus, she will need to mix 5.7 liters of the 5% solution.
Since 10 - x be the amount of 40% solution used , then;
the amount of 40% solution = 10 - 5.7 = 4.3 litres
Answer:
Step-by-step explanation:
w=204.8
Answer:
The required drawing showing the cliff, river, and tower as well as the details in the question is attached, please find alongside the answer
The width of the river is approximately 51.55 meters
Step-by-step explanation:
The height of the observation tower = 11 meters
The angle of elevation of the cliff top and the opposite side of the river = 20°
The angle of elevation of the tower top and the opposite side of the river = 30°
Therefore, by sine rule, we have;
h/sin(20) = w/sin(60)
11/sin(10) = length, l/sin(60)
l = sin(60) ×11/sin(10) ≈ 54.86 meters
w = l × cos (20) = 54.86 meters × cos (20) ≈ 51.55 meters
The width, w, of the river is approximately 51.55 meters.