The cosine of an angle is equal to the adjacent side divided
by the hypotenuse. In a right triangle, the hypotenuse is the longest side. Its
value is 13. It also follows that B is the adjacent side.
To solve for B,
B = 13 cos 22.6˚ = 12
The tangent of the angle is equal to the opposite side
divided by the adjacent side. Since B is known, therefore the answer is
tan(22.6˚<span>) = a/12<span> </span></span>
Then the original price was $42
Because it is half off we multiply 21 by 2 and get 42.
It is wrong c is the correct answer I think
Answer:
The speed is still water is
.
Step-by-step explanation:
Dimentionally speaking, speed is distance divided by time. Since, the person is travelling downstream, absolute speed is equal to the sum of current speed and speed of the person regarding current. Both components are constant. That is:

Where:
- Current speed, measured in miles per hour.
- Speed of the person regarding current, measured in miles per hour.
- Distance travelled downstream, measured in miles.
- Time spent on travelling, measured in hours.
Speed in still water occurs when current speed is zero. Then, such variable is obtained after subtracting current speed on both sides of the expression. Hence:

The speed is still water is
.