@Test
public void testAcos() {

    assertEquals((float)Math.PI, FastMath.acos(-2.0f), 0.01f);
    assertEquals(0.0f, FastMath.acos(2.0f), 0.0f);
    assertEquals(1.57f, FastMath.acos(0.0f), 0.01f);
    assertEquals(1.047f, FastMath.acos(0.5f), 0.01f);
    assertEquals(0.0f, FastMath.acos(Float.POSITIVE_INFINITY), 0.0f);
    assertEquals(0x1.921fb6p+1f, FastMath.acos(-0x1p+113f), 0.01f);
}