Why does tan equal to sin/cos? - Socratic
2015年4月15日 · The best answer to this question depends on the definitions you're using for the trigonometric functions: Unit circle: t correspond to point (x,y) on the circle x^2+y^2 =1 Define: …
What is the value of cos(pi/4)? - Socratic
2018年4月13日 · sqrt2/2 As you can see in the table above, cos45^@ or cospi/4 radians is the same thing as sqrt2/2 An alternative way is looking at the unit circle: We know that the cosine …
Half-Angle Identities - Trigonometry - Socratic
The half-angle identities are defined as follows: #\mathbf(sin(x/2) = pmsqrt((1-cosx)/2))# #(+)# for quadrants I and II
What does cosx sinx equal? - Socratic
2016年3月7日 · Which is the double angle formula of the sine #cos(x)sin(x)+sin(x)cos(x)=sin(2x)# But since we multiplied by 2 early on to get to that, we need to divide by two to make the …
What are the sine, cosine, and tangent of - Socratic
2018年5月15日 · sin((3pi)/4) = sqrt2/2 cos((3pi)/4) = -sqrt2/2 tan((3pi)/4) = -sqrt2/2 first, you need to find the reference angle and then use the unit circle. theta = (3pi)/4 now to find the …
Double Angle Identities - Trigonometry - Socratic
You would need an expression to work with. For example: Given #sinalpha=3/5# and #cosalpha=-4/5#, you could find #sin2 alpha# by using the double angle identity
Is sine, cosine, tangent functions odd or even? | Socratic
2015年2月28日 · y = cos x is always going to be even, because cosine is an even function. For example, cos #pi/4# in the first quadrant is a positive number and cos #-pi/4# (same as cos …
How do you evaluate sine, cosine, tangent of - Socratic
2016年12月14日 · (opposite over adjacent) I teach that #x^2+x^2=1# is the Pythagorean Theorem for the isosceles right triangle with a hypotenuse = 1. To solve, you get #2x^2=1#, so …
What is sine, cosine and tangent? - Socratic
2016年3月20日 · Three of the names are sine, cosine and tangent, depending which sides you divided. Sine is answer that you get when you divide the length of the side opposite an angle …
What does sec x equal in terms of sin, cos, and/or tan?
2015年9月15日 · sec alpha=1/cos alpha This comes straight from the definition. Secans is defined as inverse of cosine.