How to solve pi - Texas Instruments TI-15 Explorer Calculator

Learn the equivalence.
180 deg=pi RADIANS.
1 DEG= (Pi/180) rad.
1 rad= (180/Pi) degrees.

Is this a right circular cone or a right circular cylinder?
Volume of cylinder= Pi*(r^2)*h
Volume of cone is 1/3 of volume of cylinder with same height and radius.
Solve for h
h=(Volume)/(PI*r^2) for cylinder

How do I solve the SEEK PI problem on my car radio, every minute my radio goes off and on because of SEEK PI

You need a cone with a volume of 150 gallons.
The volume of a right circular cone is given by the formula
V_cone=(Area of base *height)/3
Since cone is circular , its base is a disk with a certain radius r. The formula becomes PI*(r^2)*h/3
As you see there are two variables, the radius and the height. There is an infinite number of combinations (radius, height) that will give you a total volume of 150 gallons. You can choose the radius (r) and solve for h, or you can choose the height then solve for the radius.
I suggest you convert gallons to cubic feet or to cubic meters then put
V=Pi*(r^2)*h/3 where V is the value of volume after conversion.
If you choose the radius, then to isolate h, h=(3*V)/(Pi*r^2)
If you choose the height, then to solve for r
r^2=(3V)/(Pi*h)
and r=square root of (3V/(Pi*h))
Now, it is your turn to carry out the rest of the calculation.
It will consist of the value of the radius, and the value of the height.
If the cone is not right circular, the situation becomes more complicated.

The circumference of a circle is C=2 * pi * r or C= pi * d.

What do we know? C=47.1 and pi.

What are we trying to calculate? d

Put what we know in the equation and solve for d.

47.1 = pi * d

To isolate d, we have to divide both sides by pi.

47.1
------ = d
pi

I get 14.99' or approximately 15' as the diameter.

Good luck,
Paul

Press 2 ^ 2ND ^ ENTER .

If you get a symbolic result, press diamond ENTER .

Divide both sides by pi to get A/pi = r^2

You are not using the right units. The integrals of functions involving angles (trigonometric functions) that you find in tables and other refrerences are valid only for the natural angle unit which is the radian. With any other angle unit (degree, gradian) there is a scale factor to take into account. That is the factor yoy are complaining about.

If it were not the case, the same integral will have two different values depending on the unit you use: and that cannot be.

If you want the calculator to give you the standard integrals in reference tables you must set the default angle unit to be radian.

Let x_deg be an angle in degrees and x_rad the corresponding value in radians.
180 deg=Pi rad
x_deg/180=x_rad/Pi
x_deg =(180 deg/PI)*x_rad
calculating the differentials of bot sides you obtain
dx_deg= (180/Pi) dx_rad

Similarly, with grads
dx_gr=(200/Pi)*dx_rad

Since X = pi, (3.141592...) I'm going to assume the problem is in radians not degrees.
Substitute pi in for X in the first equation and you get y = 4 sin(pi)
The sin of pi radians is zero.
Therefore, y = 4 * 0 = 0

I hope this helps you out.

http://en.wikipedia.org/wiki/Pi
Image here http://www.swiss-miss.com/wp-content/uploads/legacy/photos/uncategorized/2008/03/14/pi_symbol.jpg