# How do you use sum and difference identities to find the exact value of sin75?

trun it into sin( 45 + 30 ).

sin ( 45 + 30 ) = sin30cos45 + cos30sin45

sin30cos45 + cos30sin45 = (1/2)((sqrroot2)/2) + ((sqrroot3)/2)((sqrroot2)/2)

(1/2)((sqrroot2)/2) +((sqrroot3)/2)((sqrroot2)/2)=((sqrroot2)/4) + ((sqrroot6)/4)

((sqrroot2)/4) + ((sqrroot6)/4)= ((sqrroot2) + (sqrroot6)) /4

### What is the difference between exact value and true value?

Exact value is the value that is correct in measurements, such as cm, km, and etc. It is widely used in fields of science and math. However, true value is used when reviewing the art work, or etc., such as saying this piece of art drawn by somebody has a true value. It means that it is very high when estimating the value of a certain thing. It is widely used in fields of ART…

### Could you find the circumference of a circle using the exact value for pi?

Yes, you could if you knew the exact value for pi as well as the diameter of the circle. Multiply the diameter by the exact value for pi to get the circumference. However, it is impossible because the exact value for pi is not known. It is only known to about a trillion decimal places, but the exact value is not known.

### What is the exact value of pi x100000000000000000000000000000000000000?

The exact value could never be expressed as a number, as pi is an irrational number. The integer value would be: 31415926535897932384626433832795028841 If you want a slightly more accurate value: 31415926535897932384626433832795028841.9716939937510582097494 If you want an exact value: ∞ (∫e-x² dx)2 × 1038 -∞

### How do you find the exact value with percent error and your result?

To find the exact value you could: use exact values rather than estimates - as inputs; use exact formula instead of approximations, use calculus. There are other methods as well and the choice depends on the circumstances. Then, if Y is your value and E is the exact value, percentage error = 100*(Y - E)/E or 100*(Y/E - 1).

### What are identities trigonometry?

Identities are "equations" that are always true. For example, the equation sin(x) = cos(x) is true for x = pi/4 + kpi radians where k is any integer [ = 45 + 180k degrees], but for any other value of x the equation is not true. By contrast, the equation sin2(x) + cos2(x) = 1 is true whatever the value of x. This is an identity.

### What is the difference between an exact answer and an approximated answer when dealing with circles?

Usually, in terms of school work, an exact answer leaves pi in the answer. Since pi is an irrational number, as soon as you try to substitute a value for it in your calculations, you are introducing an approximation. So, for a circle with radius 5 cm, a circumference given as 10*pi cm is an exact answer but 31.4159 cm is an approximation.

### What is a reasponsable estimate of the difference of 697 and 319?

700 - 320 = 380. The exact value, which is easy enough to calculate rather than waste your time with estimates and then worry about errors and so forth, is 378. 700 - 320 = 380. The exact value, which is easy enough to calculate rather than waste your time with estimates and then worry about errors and so forth, is 378. 700 - 320 = 380. The exact value, which is easy enough to…