The equation x3+ 6x2− 2x+ 4 = 0 has roots α, β and γ. Find the value of: i) α+β+γ and αβ+βγ+γα ii) α2+β2+γ2
In the diagram above O is the centre of the circle. Points A, B and C all lie on the 2 circumference of the circle. If <OAB = α find the size of <ACB. Give reasons for your answer.
In trying to solve x-2x-3<4x-2 over its natural domain in the set of real numbers, three students produce the following inequalities. Student I (x−2)x− 2 < 4(x-3) Student II p (x−2)3(x−3)< 4(x−3)2 Student III (x−2)2(x−3) < 4(x−3)2 x− 2 Which students are still on track to obtain the correct solution set? (A) Just student II (B) Student III only (C) Both students II and III but not student I (D) All three students
A person on horizontal ground is looking at an aeroplane A through a telescope T. The aeroplane is approaching at a speed of 80m Is at a constant altitude of 200 meters above the telescope. When the horizontal distance of the aeroplane from the telescope is x metres, the angle of elevation of the aeroplane is e radians. (i) Show that θ=tan-1200x (ii) Show thatdθdt=16000x2+40000 (iii) Find the rate at which θ is changing when θ=π4 , (answer in degrees)
A group of 4 women and 8 boys include a mother and son. From this group, a team consisting of 2 women and 2 boys is to be chosen. How many ways can the team be chosen if the mother and son cannot be on the team together?
Solve 3x<2.
In the diagram above AB is a diameter of the circle, T P is a tangent at point T, O is the centre of the circle and <ATP = 111°. Find <BAT giving reasons.
If the roots of the quadratic equation 8x2 -5x+ a = 0 are sin θ and cos 2θ for some angle θ, find the possible values of a.
The rate at which a cool object warms in air is proportional to the difference between i ts temperature T, in degrees Celsius, and the constant ambient temperature A°C of the surrounding air. This rate can be expressed by the differential equation: dTdt= k(A − T) where t is time in minutes and k is a positive constant. The solution of this differential equation is T = A + Be-kt, where B is a constant. (You need NOT show this.) A bottle of baby milk is at 4 3°C when it is removed from a refrigerator and placed on the kitchen bench where the room temperature is 22°C. Five minutes later it has warmed to 12°C. Find the temperature of the milk after a further three minutes sitting on the bench. Give your answer correct to the nearest degree.
Consider the region enclosed by the upper semicircle y=a2-(x-a)2 and the vertical line x=b where 0 < b < 2a, shown shaded in the diagram above. A spherical cap is generated by rotating this region around the x-axis. Show that the volume V, in cubic units, of this solid is given by: V=πb23(3a-b).
In the diagram above, a spherical vase of radius 10 cm is being filled with water at a constant rate 90 cm3/min. Let h cm be the depth of the water after t minutes. Find the rate at which the depth of the water is rising at the instant when the depth is 5 cm. Give your answer in terms of π.
In the diagram above, points A and B are separated by a horizontal distance R and point B is located H metres higher than A. Define the angle of inclination of B from A as α. Define the origin for both motions at point A and positive directions as right and up respectively. At the same instant, identical projectiles are launched from each location directed towards each other. The projectile from A is fired with initial speed U m/s at an angle θ above the horizontal while the object launched from B has only half as much initial speed but the same angle of elevation above the horizontal. Consequently, the equations of motion for the projectile from A, t seconds after launch, are as follows: xA= Utcosθ yA= U tsin θ-12gt2 . Similarly for the projectile from B: xB=R-Utcosθ2 , yB=H+Utsinθ2-12gt2 [Do NOT prove these equations.] Given that the projectiles collide, show that this requires tan α =1 3tan θ
The velocity v of a particle moving in a straight line is governed by the equation v = x−2, where x is its displacement. The particle started at x= 5. What is the displacement function of the particle? (A) x = 5et (B) x = 2 +13et (C) x = 2 + et (D) x = 2 + 3et
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