Question
Find the max. and min. value of
y = 7cosA + 24sinA
Joshi sir comment
7cosA + 24sinA
= 25[7cosA/25 + 24sinA/25] = 25[cosAcosB + sinAsinB] where tanB = 24/7
= 25cos[A-B] max and min of cos[A-B] = 1 and -1
so max. = 25 and min. = -25
Read 3 Solution.
when A= zero degree it will be min as sin=0 and cos=1 thus value is y=7 but if negative value is allowed so use A=180 y=-7 now max when A=90 cos =0 sin=1 max value=24 of y
SARIKA SHARMA 10 year ago
is this solution helpfull: 4 3
for min 180 deg
for max 90 deg
SARIKA SHARMA 10 year ago
is this solution helpfull: 5 2
Use the property,
The Maximum and Minimum value of asinx +bcosx is Root(a2 + b2) and - root(a2 + b2)
HEMANT DESAI 10 year ago
is this solution helpfull: 2 1