
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Is there a real number $a$ such that the function $y=\sin^2x+a\cos x+ \frac{5}{8}a- \frac{3}{2}$ has a maximum value of $1$ on the closed interval $\left[0,\frac{\pi}{2}\right]$? If it exists, find the corresponding value of $a$. If not, explain why.

Present the answer in LaTex format: \boxed{Your answer}
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