# What is scalar product of a=2i-3j, b=6i+4j?

sciencesolve | Teacher | (Level 3) Educator Emeritus

Posted on

Remember the formula of dot scalar product:

`bar a` * `barb` = |bara|*|barb|*cos theta

theta is the angle between bara and barb

|a| is the magnitude of the vector a: bara = sqrt(2^2 + (-3)^2)

bara = sqrt 13

|b| is the magnitude of the vector b:

`barb = sqrt(6^2 + 4^2)` `bara = sqrt 52 = 2sqrt13`

`` `bara*barb = (sqrt13)*(2sqrt13) cos theta`

The scalar product is `bara*barb`  =26 cos `theta`  .
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "url": "http://www.enotes.com/homework-help/what-scalar-product-2i-3j-b-6i-4j-299443", "fetch_time": 1477455590000000000, "content_mime_type": "text/html", "warc_filename": "crawl-data/CC-MAIN-2016-44/segments/1476988720615.90/warc/CC-MAIN-20161020183840-00105-ip-10-171-6-4.ec2.internal.warc.gz", "warc_record_offset": 442708084, "warc_record_length": 9650, "token_count": 189, "char_count": 516, "score": 3.578125, "int_score": 4, "crawl": "CC-MAIN-2016-44", "snapshot_type": "latest", "language": "en", "language_score": 0.6510979533195496, "file_path": "/sailhome/yjruan/project/latent-lm/data/processed/finemath-4plus/finemath-4plus/train-00029-of-00064.parquet"}