题目

I love snakes. My mom definitely does not. When she was a kid, snakes used to hide in warm spots under the furniture. So she grew up afraid she’d step on a snake. I grew up hoping I’d see one... outside! Lots of people who are afraid of snakes have never even seen one. So where does our fear come from?Scientists wonder about this too. Their experiments with adults, kids, and even babies show that it’s complicated. People may not be born afraid of snakes, but we are born able to see them quickly. In tests with pictures, people picked out snakes faster than they could find flowers, frogs, 已知函数f（x）=23cosxsinx+2cos2x（1）求f（4π3）的值；（2）当x∈[0，π2]时，求函数f（x）的值域．