true
randRangeNonZero( -90, 90 ) * 5
ANGLE*2*PI/360
ANGLE + "^{\\circ}"
randFromArray( [ "cos", "sin" ] )
{ "cos": "cosine", "sin": "sine"}[FN]
{ "cos": "x", "sin": "y"}[FN]
roundTo(3, { "cos": Math.cos(ANGLE * (Math.PI/180)), "sin": Math.sin(ANGLE * (Math.PI/180)) }[FN])
\FN(PRETTY_ANGLE) = \text{?}
SOLUTION
angle
// Convert guess to an angle between 0 and 2*PI for comparison
var revolutions = floor(guess / (2 * PI));
var modified_guess = guess - revolutions*2*PI;
// Convert answer to an angle between 0 and 2*PI
revolutions = floor(ANGLE_RADIANS / (2 * PI));
var modified_angle = ANGLE_RADIANS - revolutions*2*PI;
// If the angle is at zero, assume that it was not set.
// If the student knows the answer be memory, don't require
// them to set the angle.
if (abs(guess) < 0.001) return true;
// Verify that the angles match
return abs( modified_angle - modified_guess ) < 0.001;
KhanUtil.setAngle( guess );
Move the orange point around the unit circle to the angle indicated inside the FNNAME expression above.
Indicate the FNNAME value in the answer field.
initUnitCircle( DEGREES );
To find the FNNAME using the unit circle, first find the angle.
Drag the orange point around the circle until PRETTY_ANGLE
is selected.
The correct angle is selected. Remember, the FNNAME of an angle is represented by the
COORD
coordinate of a point on the unit circle.
goToAngle( ANGLE );
The COORD
coordinate of the point is SOLUTION
,
so \FN(PRETTY_ANGLE) = SOLUTION
.
goToAngle( ANGLE );
showCoordinates( ANGLE );
false
randFromArray([
-6*PI/2, -5*PI/2, -7*PI/3, -9*PI/4,
-2*PI, -11*PI/6, -7*PI/4, -5*PI/3, -3*PI/2, -4*PI/3, -5*PI/4, -7*PI/6,
-PI, -5*PI/6, -3*PI/4, -2*PI/3, -PI/2, -PI/3, -PI/4, -PI/6, -PI/12,
PI/12, PI/6, PI/4, PI/3, PI/2, 2*PI/3, 3*PI/4, 5*PI/6, PI,
7*PI/6, 5*PI/4, 4*PI/3, 3*PI/2, 5*PI/3, 7*PI/4, 11*PI/6, 2*PI,
9*PI/4, 7*PI/3, 5*PI/2, 6*PI/2
])
ANGLE
piFraction(ANGLE)
randFromArray( [ "cos", "sin" ] )
{ "cos": "cosine", "sin": "sine"}[FN]
{ "cos": "x", "sin": "y"}[FN]
roundTo(3, { "cos": Math.cos(ANGLE), "sin": Math.sin(ANGLE) }[FN])