Identify Integral: Identify the integral to be solved. I=∫sin2(x)+4sinx−1cosxdx
Simplify Expression: Simplify the expression inside the square root if possible.The expression under the square root is a quadratic in terms of sin(x), which can be factored or completed to a square if it represents a perfect square trinomial.
Factor Quadratic: Attempt to factor the quadratic expression sin2(x)+4sinx−1. The quadratic does not factor easily into real factors, so we consider completing the square to transform it into a form that might be more easily integrated. sin2(x)+4sinx−1=(sin(x)+2)2−5
Rewrite Integral: Rewrite the integral with the completed square. I=∫(sin(x)+2)2−5cosxdx
Look for Substitution: Look for a substitution that will simplify the integral. Let u=sin(x)+2, then du=cos(x)dx. This substitution will simplify the integral.
Perform Substitution: Perform the substitution.I=∫u2−51du
Recognize Standard Form: Recognize the integral as a standard form. The integral ∫u2−a21du is a standard form that corresponds to the inverse hyperbolic function arcsinh(au) or the logarithmic form ln∣u+u2−a2∣.
Integrate Using Form: Integrate using the standard form. I=ln∣u+u2−5∣+C, where C is the constant of integration.
Substitute Back: Substitute back to the original variable.I=ln∣sin(x)+2+(sin(x)+2)2−5∣+C
Simplify Final Answer: Simplify the final answer if possible.I=ln∣sin(x)+2+sin2(x)+4sin(x)−1∣+C
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