Formula for compound interest is
Interest = Amount - Principal
Interest = 
- P
Where r = rate in percent
t = time in years
For Jaina,
P = $300
r= 7%
t = 3 yrs
So, Interest = 
- 300
For Tomas
P = $400
r= 4%
t = 3 yrs
So, Interest = 
- 400
So pair of equations for Jaina and Tomas are
Interest = - 300
Interest = - 400
We can divide each digit by 7. So 56/7=8 and 21/7=3
so.... 8:3
A generic point on the graph of the curve has coordinates
The derivative gives us the slope of the tangent line at a given point:
Let k be a generic x-coordinate. The tangent line to the curve at this point will pass through 
and have slope 
So, we can write its equation using the point-slope formula: a line with slope m passing through 
has equation
In this case, 
and 
, so the equation becomes
We can rewrite the equation as follows:
We know that this function must give 0 when evaluated at x=0:
This equation has no real solution, so the problem looks impossible.
Equation of a line passing through point (x1, y1) with slope m is given by y - y1 = m(x - x1)
For parallel lines, the slope of the required line is equal to the slope of the given line.
x = -3 is a vertical line, therefore, the required line will also be a vertical line since they are parallel.
Since the required line passes through point (4, 2), the equation of the required line is x = 4.
Answer:
Take a line segment AB = 2 units (consider 1 unit = 2 cm) on x-axis.
Draw a perpendicular on B and construct a line BC = 1 unit length.
Join AC which will be √5 (Pythagoras theorem). Take A as center, and AC as radius draw an which cuts the x-axis at point E.
The line segment AC represents √5 unit
