Use an appropriate method to find the root of x³ + x + 1 = 0 correct to 2 decimal places. Start with initial interval -0.8 and -0.6. Show all working.
Human blood pressure P (in mm of mercury) varies periodically with time (t in seconds). The first time during the first second of a cycle when the pressure P is 90 mm can be expressed by:
80 + 300t - 2700t³ = 90
f(t) = 2700t³ - 300t + 10 = 0
Take an initial value of t = 0.05 seconds and use a method different to Question One to find a solution to f(t) = 0 accurate to 4 decimal places.