Saved Bookmarks
| 1. |
Find the range of the function f(x) = 1 + 3 cos2x |
|
Answer» Given: f (x) = 1 + 3 cos2x To find: the range of function Explanation: So, the range of a function consists of all the second elements of all the ordered pairs, i.e., f(x), so we have to find the values of f(x) to get the required range Given, f (x) = 1 + 3 cos2x We know the value of cos 2x lies between -1, 1, so -1≤ cos 2x≤ 1 Multiplying by 3, we get -3≤ 3cos 2x≤ 3 Adding with 1, we get -2≤ 1 + 3cos 2x≤ 4 Or, -2≤ f(x)≤ 4 Hence f(x)∈ [-2, 4] Hence the range of f = [-2, 4] |
|