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The mass, m grams, of a substance is increasing exponentially so that the mass at time t hours is m=250e^(0.021t). Find the time taken for the mass to double in value.

All exponential equations can be reduced to the form m=m 0 e kt , where m 0 is the initial mass. This means for our equation the initial mass is 250g. If the mass has doubled in size, then m now equals 2*250...
TJ
Answered by Tom J. • Maths tutor
9143 Views

How can I determine the stationary points of a curve and their nature?

For example, y = 3x 3 + 9x 2 + 2. Determine the stationary points and their nature. Let's remind ourselves what a stationary point is, and what is meant by the nature of the points. A stationary point is a p...
TD
Answered by Tutor87017 D. • Maths tutor
175349 Views

Find all the solutions of 2 cos 2x = 1 – 2 sinx in the interval 0 ≤ x ≤ 360°.

We know that having cos and sin functions in a question is going to cause us problems - we need a single function of x. So, step 1, we need to rewrite sin or cos in terms of the other. How do we choose which...
NH
Answered by Nicola H. • Maths tutor
24359 Views

Facebook est une perte de temps, êtes-vous d'accord?

Facebook est le réseau social actuellement le plus utilisé au monde avec plus d'un milliard d'utilisateurs dans le monde et 25 millions en France. Il peut être juste de penser qu'il représente une perte de t...
SR
Answered by Sigrid R. • French tutor
6849 Views

Describe how an antibody works?

Binding sites on the antibody are complementary to specific binding sites on antigen. Antibodies group together/in groups of 5 (pentamers) and attach to antigen presenting pathogens, forming antigen-antibody...
AP
Answered by Adam P. • Biology tutor
3237 Views