Question
Question: The value of\(\cos \theta \) increases as \(\theta \) increases. Enter 1 for true and 0 for false....
The value ofcosθ increases as θ increases. Enter 1 for true and 0 for false.
Solution
Hint: Look at the graph of cosine and check in the interval from 0 to 180. If the value of cosθ increases as θ increases then the answer is 1 else it is 0.
Complete step-by-step answer:
For a right angled triangle, the ratio of the sides gives certain trigonometric functions.
cosθis the ratio of the base and the perpendicular. So, cosθ=cb.
Similarly, one can get the other trigonometric ratios as well by taking different sets of sides.
For different angles, one can plot the variation of this function with the varying angleθ.
The graph of cosθlooks like:
The cosine function has the following properties:
It is a decreasing function from 0 to 180.
It is symmetric about the y axis.
It has 2π as its period.
In the interval 0 to 90 we can see that as the angle θ is increasing the function cosθ will decrease from 1 to 0 and on further going from 90 to 180 the function takes values from 0 to -1. So, it is clear from the graph that the cosine function decreases in the interval 0 to 180.
So, the correct answer is a false so we enter 0.
Note: Since no interval was mentioned in the question the standard domain of 0 to 180 was taken. Otherwise, the graph is a sinusoidal curve and is either decreasing or increasing, according to the interval.