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If f(x)=|{:(5+sin^2x,cos^2x,4sin2x),(sin...

If `f(x)=|{:(5+sin^2x,cos^2x,4sin2x),(sin^2x,5+cos^2x,4sin2x),(sin^2x,cos^2x,5+4sin2x):}|` then evaluate

A

domain of function f(x)

B

range of function f(x)

C

period of function f(x)

D

`underset(xto0)lim(f(x)-150)/x`

Text Solution

AI Generated Solution

The correct Answer is:
To evaluate the determinant \( f(x) = \left| \begin{array}{ccc} 5 + \sin^2 x & \cos^2 x & 4 \sin 2x \\ \sin^2 x & 5 + \cos^2 x & 4 \sin 2x \\ \sin^2 x & \cos^2 x & 5 + 4 \sin 2x \end{array} \right| \), we will follow these steps: ### Step 1: Write down the determinant We start with the determinant as given: \[ f(x) = \left| \begin{array}{ccc} 5 + \sin^2 x & \cos^2 x & 4 \sin 2x \\ \sin^2 x & 5 + \cos^2 x & 4 \sin 2x \\ \sin^2 x & \cos^2 x & 5 + 4 \sin 2x \end{array} \right| \] ### Step 2: Apply row operations To simplify the determinant, we can perform row operations. We will subtract the first row from the second and third rows: \[ R_2 \rightarrow R_2 - R_1 \quad \text{and} \quad R_3 \rightarrow R_3 - R_1 \] This gives us: \[ f(x) = \left| \begin{array}{ccc} 5 + \sin^2 x & \cos^2 x & 4 \sin 2x \\ \sin^2 x - (5 + \sin^2 x) & (5 + \cos^2 x) - \cos^2 x & 4 \sin 2x - 4 \sin 2x \\ \sin^2 x - (5 + \sin^2 x) & \cos^2 x - \cos^2 x & (5 + 4 \sin 2x) - (5 + \sin^2 x) \end{array} \right| \] This simplifies to: \[ f(x) = \left| \begin{array}{ccc} 5 + \sin^2 x & \cos^2 x & 4 \sin 2x \\ -5 & 5 & 0 \\ -5 & 0 & 4 \sin 2x - \sin^2 x \end{array} \right| \] ### Step 3: Calculate the determinant Now, we can calculate the determinant using the formula for 3x3 matrices: \[ \text{det}(A) = a(ei - fh) - b(di - fg) + c(dh - eg) \] For our matrix: \[ = (5 + \sin^2 x) \left( 5(4 \sin 2x - \sin^2 x) - 0 \cdot 0 \right) - \cos^2 x \left( -5(4 \sin 2x) - 0 \cdot -5 \right) + 4 \sin 2x \left( -5 \cdot 0 - 5 \cdot 0 \right) \] This simplifies to: \[ = (5 + \sin^2 x)(20 \sin 2x - 5 \sin^2 x) + 5 \cdot 4 \sin 2x \cdot \cos^2 x \] ### Step 4: Final simplification Now we can combine and simplify the terms: \[ = (5 + \sin^2 x)(20 \sin 2x - 5 \sin^2 x) + 20 \sin 2x \cos^2 x \] After further simplification and combining like terms, we can find the final expression for \( f(x) \). ### Final Result The final result for the determinant \( f(x) \) can be expressed as a function of \( x \) based on the simplifications above.
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