A cross-section of a micro-fluidic channel is modeled by the curve with equation
3x2y−bx3+12y2=4 3x^2y - bx^3 + \frac{1}{2}y^2 = 4 3x2y−bx3+21y2=4where bbb is a positive constant.
Show that
dydx=3x(bx−2y)3x2+y \frac{dy}{dx} = \frac{3x(bx - 2y)}{3x^2 + y} dxdy=3x2+y3x(bx−2y)Given that the curve has a stationary point at x=1x = 1x=1, determine the value of bbb.
425 exam-style questions on OCR A Level Maths 1.7 Differentiation, covering 1.7.1 Derivative as gradient of the tangent, 1.7.2 Gradient of the tangent at a point, 1.7.3 Sketching the gradient function, 1.7.4 Second derivatives, 1.7.5 Second derivative as rate of change of gradient, 1.7.6 Convex, concave and points of inflection (A-level only), 1.7.7 Differentiation from first principles for powers of x, 1.7.8 Differentiation from first principles for sin x and cos x (A-level only), 1.7.9 Differentiating x^n, 1.7.10 Differentiating e^(kx) and a^(kx) (A-level only), 1.7.11 Differentiating trigonometric functions (A-level only), 1.7.12 Derivative of ln x (A-level only), 1.7.13 Tangents and normals, 1.7.14 Stationary points, 1.7.15 Increasing and decreasing functions, 1.7.16 Points of inflection (A-level only), 1.7.17 Product and quotient rules (A-level only), 1.7.18 Chain rule (A-level only), 1.7.19 Parametric and implicit differentiation (A-level only), 1.7.20 Constructing differential equations (A-level only), and 1.7 Differentiation. Each one has a worked solution and a mark scheme showing where the marks go.