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A mathematical problem about trigonometric function
f(x)=cos? x+2psinx+q= 1-sin? x+2psinx+q=-sin? x+2psinx+q+ 1=-(sinx-p)? +p? +q+ 1,

If x∈[0, π/2], then 0≤sinx≤ 1,

Let sinx=t, t∈[0, 1],

Function y=-(t-p)? +p? +q+ 1 is a quadratic function about the downward opening of t, and the symmetry axis is t=p(t∈[0, 1]).

Suppose there are p∈Z and q∈Z so that the function y=-(t-p)? +p? The value range of +q+ 1(t∈[0, 1]) is [7, 10].

When p≥ 1 and p∈Z, y=-(t-p)? +p? +q+ 1 is a monotonically increasing function on [0, 1].

What is the function value when the maximum value is t= 1 =- 1 +2p× 1+q+ 1 = 2p+q = 10,

What is the function value when the minimum value is t=0 =-0? +2p×0+q+ 1=q+ 1=7,

The solution is q = 6, p = 2 >;; 1,

When p≤0 and p∈Z, y=-(t-p)? +p? +q+ 1 is a monotonically decreasing function on [0, 1].

What is the function value when the maximum value is t=0 =-0? +2p×0+q+ 1 = q+ 1 = 10,

What is the function value when the minimum value is t= 1 =- 1 +2p× 1+q+ 1=2p+q=7,

Q = 9,p =- 1

To sum up, there are p=2, q=6, or p=- 1, q=9, which makes the range of f(x) [7, 10].