Question

find the minimum value of f(x)=(4/5)sin2x-3/5

Answer 1

hint : the minimum value of the sine of an angle is -1

Answer 2

@cwrw238 so then is the answer just -1 or how do I plug it in?

Answer 3

plug in sin 2x = -1

Answer 4

sine has min value of -1 so (4/5)(-1)-(3/5)
=-7/5

Answer 5

@cwrw238 @heybhai ok so even though its like a double angle or something the minimum is always -1?

Answer 6

see this @ses11 http://www.google.com/imgres?imgurl=http://math.ucsd.edu/~wgarner/math10a/triggraphs_files/image006.gif&imgrefurl=http://math.ucsd.edu/~wgarner/math10a/triggraphs.htm&h=125&w=251&sz=2&tbnid=32SeEnqvAtw4BM:&tbnh=62&tbnw=124&zoom=1&usg=__xYAFg7sLbBpvd_Mp4Uy2epgDCS0=&docid=jMlqUfKA3s7L1M&sa=X&ei=SE35UYXAKYSBrgfB_ICACA&ved=0CC0Q9QEwAA&dur=3035

Answer 7

yes

Answer 8

always sin and cos always oscillate between 1 and -1

Answer 9

@heybhai @cwrw238 THANK YOU SO MUCH!!!

Answer 10

welcome