Q. Find dxdy by implicit differentiationtan(4x+y)=4x
Differentiate with respect to x: Differentiate both sides of the equation with respect to x. The left side of the equation involves the tangent of a sum, which requires the use of the chain rule for differentiation. The right side is a simple derivative of a linear term. Differentiate tan(4x+y) with respect to x: dxd[tan(4x+y)]=sec2(4x+y)⋅dxd(4x+y) Differentiate 4x with respect to x: dxd[4x]=4
Apply chain rule: Apply the chain rule to the left side of the equation.The derivative of 4x+y with respect to x is 4+(dxdy) because y is a function of x and its derivative with respect to x is (dxdy).So, sec2(4x+y)⋅dxd(4x+y) becomes sec2(4x+y)⋅(4+(dxdy))
Set derivatives equal: Set the derivatives from both sides equal to each other. sec2(4x+y)⋅(4+dxdy)=4
Solve for (\frac{dy}{dx}): Solve for \((\frac{dy}{dx}).\(\newlineTo isolate (\frac{dy}{dx}), we need to move all terms not involving \((\frac{dy}{dx}) to the other side of the equation.\(\newline\sec^\(2(4x+y) \cdot (\frac{dy}{dx}) = 4 - \sec^2(4x+y) \cdot 4(\frac{dy}{dx}) = \frac{\(4\) - \(4\)\cdot\sec^\(2\)(\(4\)x+y)}{\sec^\(2\)(\(4\)x+y)}
Simplify expression: Simplify the expression for \((\frac{dy}{dx}). We can factor out the 4 on the right side of the equation to get: (dxdy)=4×sec2(4x+y)(1−sec2(4x+y))
Apply trigonometric identity: Recognize that 1−sec2(θ) is equal to −tan2(θ). This is a trigonometric identity. Applying this identity, we get: (dy/dx)=4×(−tan2(4x+y))/sec2(4x+y)
Correct previous mistake: Realize that there is a mistake in the previous step. The trigonometric identity used in the previous step is incorrect. The correct identity is 1−tan2(θ)=sec2(θ). Therefore, the simplification made in Step 6 is not valid. We need to correct this mistake.
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