A chemical reactor's internal pressure PPP, measured in kilopascals (kPa), increases over time ttt (minutes) according to the model
P=34t2+12,t≥0 P = \frac{3}{4}t^2 + 12, \quad t \ge 0 P=43t2+12,t≥0A monitoring system tracks the pressure until it reaches a critical threshold of 39 kPa. The finite region R R\,R in the first quadrant of the ttt-P P\,P plane is bounded by the PPP-axis, the horizontal line P=39P = 39P=39, and the curve representing the reactor's pressure.
Calculate the exact area of RRR.
438 exam-style questions on OCR A Level Maths 1.8 Integration, covering 1.8.1 Fundamental theorem of calculus (A-level only), 1.8.2 Integrating x^n, 1.8.3 Integrating standard functions (A-level only), 1.8.4 Evaluating definite integrals, 1.8.5 Area between a curve and the x-axis, 1.8.6 Area between two curves, 1.8.7 Integration as the limit of a sum (A-level only), 1.8.8 Integration by substitution (A-level only), 1.8.9 Integration by parts (A-level only), 1.8.10 Use of partial fractions in integration (A-level only), 1.8.11 Differential equations with separable variables (A-level only), 1.8.12 Interpreting the solution of a differential equation (A-level only), and 1.8 Integration. Each one has a worked solution and a mark scheme showing where the marks go.