tan 315 =
sin 315 =
sec 315 =
I need help with this question! I can't remember how to do it... Can anyone help me out? Please and thank you!
sin 315 =
sec 315 =
I need help with this question! I can't remember how to do it... Can anyone help me out? Please and thank you!
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315° = 360° – 45° Let α=360 and β = 45
sin α – β = sin α cos β – sin β cos α =
sin 360 cos 45 – sin 45 cos 360 =
0•cos 45 – √2/2 •1 = –√2/2
Similarly plug into
tan α– β = (tan α – tan β)/(1 + tan α tan β)
and
sec α–β = 1/cos α–β = 1/(cos α cos β + sin α sin β )
OR The Eeeeasy way-- just draw a 45 degree angle in the 4th quadrant and read the answers from the triangle: The legs are +1 and –1 and the hypotenuse is √2.
tan 315 = –1
sin 315 = –1/√2 = –√2/2
sec 315 = √2/1 = √2
sin α – β = sin α cos β – sin β cos α =
sin 360 cos 45 – sin 45 cos 360 =
0•cos 45 – √2/2 •1 = –√2/2
Similarly plug into
tan α– β = (tan α – tan β)/(1 + tan α tan β)
and
sec α–β = 1/cos α–β = 1/(cos α cos β + sin α sin β )
OR The Eeeeasy way-- just draw a 45 degree angle in the 4th quadrant and read the answers from the triangle: The legs are +1 and –1 and the hypotenuse is √2.
tan 315 = –1
sin 315 = –1/√2 = –√2/2
sec 315 = √2/1 = √2
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Reference angle = 45 degrees
45 degree angle is in Q1, where y > 0
315 degree angle is in Q4, where y < 0
sin(315) = −sin(45) = −√2/2
In Q1, x > 0
In Q4, x > 0
cos(315) = cos(45) = √2/2
tan(315) = sin(315)/cos(315) = (−√2/2)/(√2/2) = −1
cot(315) = 1/tan(315) = −1
sec(315) = 1/cos(315) = 2/√2 = √2
csc(315) = 1/sin(315) = −2/√2 = −√2
Mαthmφm
45 degree angle is in Q1, where y > 0
315 degree angle is in Q4, where y < 0
sin(315) = −sin(45) = −√2/2
In Q1, x > 0
In Q4, x > 0
cos(315) = cos(45) = √2/2
tan(315) = sin(315)/cos(315) = (−√2/2)/(√2/2) = −1
cot(315) = 1/tan(315) = −1
sec(315) = 1/cos(315) = 2/√2 = √2
csc(315) = 1/sin(315) = −2/√2 = −√2
Mαthmφm