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If f(x) =sin x and f(a) =¾ find the value of f(a) +5f(-a)

User Shaquona
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1 Answer

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The sine function is an odd function, that is, it has the following property:


f(-x)=-f(x)

Using this property, we can find the value of f(-a):


\begin{gathered} f(a)=(3)/(4) \\ f(-a)=-f(a)=-(3)/(4) \end{gathered}

Now we can calculate the value of the expression:


f(a)+5f(-a)=(3)/(4)+5\cdot(-(3)/(4))=(3)/(4)-(15)/(4)=-(12)/(4)=-3

User Skatephone
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