cos()
Return the cosine of the argument.
Syntax
cos(radians)
Parameters
Parameter | Definition |
---|---|
radians | arc length in radians whose cosine is to be determined*Valid Values* |
Description
The cos() function returns the cosine of radians. The output range for the cos() function is -1 ≤ cos() ≤ 1.
Example
The following example uses the cos() function to draw a crude graph of a cosine waveform over a half period:
print("Cosine Waveform:\n\n");
print(" -1 -0.5 0 0.5 1\n");
print(" +----+----+----+----+\n");
i = 0.0; while (i <= 3.2) {
printf("%4.2f ",i);
cosine = cos(i);
plot = int(10 * cosine) + 10;
if (plot < 10) {
before = "";
j = 1;
while (j <= plot) {
before = before . " ";
j++;
}
after = "";
j = plot; while (j < 9) {
after = after . " ";
j++;
}
print(before,"*",after,"|");
printf(" cosine = %+8.6f\n",cosine);
}
elsif (plot == 10) {
print(" *");
printf(" cosine = %+8.6f\n",cosine);
}
else {
print(" |");
before = "";
j = 11;
while (j < plot) {
before = before . " ";
j++;
}
print(before,"*");
after = "";
j = plot + 1;
while (j <= 22) {
after = after . " ";
j++;
}
print(after);
printf("cosine = %+8.6f\n",cosine);
}
i = i + 0.1;
}
print(" -1 -0.5 0 0.5 1\n");
print(" +----+----+----+----+\n");
i = 0.0; while (i <= 3.2) {
printf("%4.2f ",i);
cosine = cos(i);
plot = int(10 * cosine) + 10;
if (plot < 10) {
before = "";
j = 1;
while (j <= plot) {
before = before . " ";
j++;
}
after = "";
j = plot; while (j < 9) {
after = after . " ";
j++;
}
print(before,"*",after,"|");
printf(" cosine = %+8.6f\n",cosine);
}
elsif (plot == 10) {
print(" *");
printf(" cosine = %+8.6f\n",cosine);
}
else {
print(" |");
before = "";
j = 11;
while (j < plot) {
before = before . " ";
j++;
}
print(before,"*");
after = "";
j = plot + 1;
while (j <= 22) {
after = after . " ";
j++;
}
print(after);
printf("cosine = %+8.6f\n",cosine);
}
i = i + 0.1;
}
The example produces the following output:
Cosine Waveform:
-1 -0.5 0 0.5 1
+----+----+----+----+
0.00 | * cosine = +1.000000
0.10 | * cosine = +0.995004
0.20 | * cosine = +0.980067
0.30 | * cosine = +0.955336
0.40 | * cosine = +0.921061
0.50 | * cosine = +0.877583
0.60 | * cosine = +0.825336
0.70 | * cosine = +0.764842
0.80 | * cosine = +0.696707
0.90 | * cosine = +0.621610
1.00 | * cosine = +0.540302
1.10 | * cosine = +0.453596
1.20 | * cosine = +0.362358
1.30 | * cosine = +0.267499
1.40 |* cosine = +0.169967
1.50 * cosine = +0.070737
1.60 *| cosine = -0.029200
1.70 * | cosine = -0.128844
1.80 * | cosine = -0.227202
1.90 * | cosine = -0.323290
2.00 * | cosine = -0.416147
2.10 * | cosine = -0.504846
2.20 * | cosine = -0.588501
2.30 * | cosine = -0.666276
2.40 * | cosine = -0.737394
2.50 * | cosine = -0.801144
2.60 * | cosine = -0.856889
2.70 * | cosine = -0.904072
2.80 * | cosine = -0.942222
2.90 * | cosine = -0.970958
3.00 * | cosine = -0.989992
3.10 * | cosine = -0.999135
3.20 * | cosine = -0.998295
-1 -0.5 0 0.5 1
+----+----+----+----+
0.00 | * cosine = +1.000000
0.10 | * cosine = +0.995004
0.20 | * cosine = +0.980067
0.30 | * cosine = +0.955336
0.40 | * cosine = +0.921061
0.50 | * cosine = +0.877583
0.60 | * cosine = +0.825336
0.70 | * cosine = +0.764842
0.80 | * cosine = +0.696707
0.90 | * cosine = +0.621610
1.00 | * cosine = +0.540302
1.10 | * cosine = +0.453596
1.20 | * cosine = +0.362358
1.30 | * cosine = +0.267499
1.40 |* cosine = +0.169967
1.50 * cosine = +0.070737
1.60 *| cosine = -0.029200
1.70 * | cosine = -0.128844
1.80 * | cosine = -0.227202
1.90 * | cosine = -0.323290
2.00 * | cosine = -0.416147
2.10 * | cosine = -0.504846
2.20 * | cosine = -0.588501
2.30 * | cosine = -0.666276
2.40 * | cosine = -0.737394
2.50 * | cosine = -0.801144
2.60 * | cosine = -0.856889
2.70 * | cosine = -0.904072
2.80 * | cosine = -0.942222
2.90 * | cosine = -0.970958
3.00 * | cosine = -0.989992
3.10 * | cosine = -0.999135
3.20 * | cosine = -0.998295
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