<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 Given the functions $y= \frac {1}{x^{2}}$, $y=2x$, $y=x^{2}+x$, and $y=\sqrt[3]{x^{5}}$, how many of these functions are power functions, i.e., can be expressed in the form $y=x^{\alpha}$ where $\alpha$ is a real number? Provide your answer as a whole number. Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
2
Given the functions $y= \frac {1}{x^{2}}$, $y=2x$, $y=x^{2}+x$, and $y=\sqrt[3]{x^{5}}$, how many of these functions are power functions, i.e., can be expressed in the form $y=x^{\alpha}$ where $\alpha$ is a real number? Provide your answer as a whole number.
test