Question
Solve for x:
sin2x + cos^2x = 1
0° < or equal to x < 360°
sin2x + cos^2x = 1
0° < or equal to x < 360°
Answers
bobpursley
That is an identity, it is true for all values of x.
Try x=-439
Try x=-439
CL
o____O
how did you get to that value? can you show me how to solve it algabraeically?
how did you get to that value? can you show me how to solve it algabraeically?
Damon
Draw a right triangle with hypotenuse c and sides a and b. Opposite angles are then A, B, C
now sin A = a/c so a = c sin A
cos a = b/c so b = c cos A
right triangle geometry says
a^2 + b^2 =c ^2
so
c^2 sin^2 A + c^2 cos^2 A = c^2
divide both sides by c^2
now sin A = a/c so a = c sin A
cos a = b/c so b = c cos A
right triangle geometry says
a^2 + b^2 =c ^2
so
c^2 sin^2 A + c^2 cos^2 A = c^2
divide both sides by c^2